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EXPERIMENTAL SECTION
General Experimental. Reagents and solvents were used as supplied commercially,
except for DCM and THF, which were distilled from CaH2 and Na/Ph2CO, respectively.
Reagents supplied as solutions were dispensed based upon manufacturer-supplied concentrations. Reactions were conducted under an atmosphere of N2 except where noted. Unless otherwise noted, reactions were performed in glassware that was flame dried and evacuated and backfilled with nitrogen. Thin-layer chromatography (TLC) was performed on 0.25 mm hard-layer silica G plates visualized with a UV lamp or by
staining: 1% ceric sulfate and 10% ammonium molybdate in 10% H2SO4 (general stain,
after heating); 3% vanillin in 3% H2SO4 in EtOH (general stain, after heating); or a 1%
N,N′-dimethyl-p- phenylenediamine in 1:20:100 acetic acid/water/methanol (specific for peroxides). Flash column chromatography was performed on 230-400M silica gel. 1H
NMR, 13C NMR and 19F NMR spectra were acquired in CDCl
3 on a Bruker Advance 400
MHz or a Bruker 300 MHz. 1H spectra are reported as chemical shift (multiplicity,
number of protons, J couplings in Hz). IR spectra were recorded as neat films on a ZrSe crystal; selected absorbances are reported wavenumbers (cm-1). Abbreviations: hexane
= Hex; EA = ethyl acetate; THF = tetrahydrofuran; THP = tetrahydropyranyl; DMF = dimethylformamide; Tf2O = trifluoromethanesulfonic anhydride; KOtBu = potassium
tert-butoxide; KOH = potassium hydroxide.
t-Butyl Hydroperoxide [75-91-2], 5.5 M in decane, was used as purchased from Sigma
Aldrich.
2-Tetrahydropyranyl (THP) Hydroperoxide [4676-84-0] was synthesized following a
known procedure.17
2-Bromoethyl trifluoromethanesulfonate [103935-47-3] was prepared (0.0422 g, 16%)
was prepared by an adapted procedure.23 2-Bromoethanol (0.1249 g, 1.0 mmol) was
added to 2,6-lutidine (2.1 mmol, 0.2250 g) and stirred at 0C. Trifluoromethanesulfonic anhydride (2.2 mmol, 0.36 mL) was added dropwise and the reaction was then stirred for 30 min before being quenched with 10% EA/Hex (~2 mL). Was passed through a short silica plug and removed solvent under reduced pressure and temperature (water bath at 10C), followed by distillation with Kügelrohr at 6 mmHg at 60C to obtain a clear colorless liquid, with the following spectral details; 1H NMR (400 MHz): 4.76 (t, 2H,
J = 6.75 Hz), 3.62 (t, 2H, J = 6.0 Hz); Rf = 0.62 (20% EA/Hex). Spectral details matched
previously reported.23
2-((2-Bromoethyl)peroxy)-2-methylpropane (1c) [56345-26-7] was prepared (0.1468 g,
25%) by adding pyridine (3.0 mmol, 0.24 mL) to THF (0.23 M, 13.0 mL), followed by dropwise addition of Tf2O for 10 minutes at 0C, which turned the clear colorless
solution opaque white. 2-bromoethanol (3.0 mmol, 0.3749 g) was added to THF (1.5 M, 2 mL) dropwise to the reaction; after 30 minutes the solution mixture was a slight
brown color and then was stirred for another 30 minutes before quenching with water. The mixture was extracted with two portions of diethyl ether (2x20 mL) and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on a rotary evaporator at reduced temperature (10C at 200 mmHg) to give a clear yellow oil of crude bromotriflate. KOtBu (3.0 mmol, 0.4039 g) and tBuOOH (3.0 mmol, 0.54 mL of 5.5 M solution in decane) with THF (1.5 M, 2 mL) were added sequentially to THF (0.3 M, 10 mL) and cooled to 0C. Crude triflate was then added with THF (1.0 M, 3 mL) dropwise to the mixture of KOtBu/tBuOOH over a period of 5 minutes. The reaction was stirred for 21 hours before being quenched with water. The mixture was extracted twice with diethyl ether (2x30 mL) and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on a rotary evaporator and purified with silica chromatography using 10% EA/Hex to furnish a clear colorless, sweet smelling liquid in with the following spectral details; 1H
NMR (400 MHz, CDCl3) 4.22 (t, 2H, J = 6.4 Hz), 3.57 (t, 2H, J = 6.4), 1.27 (s, 9H); 13CNMR
(400 MHz, CDCl3) 80.8 (C), 74.5 (C, 2H), 28.7 (C, 2H), 26.4 (3C, 6H); IR (neat) 2977,
2931, 1363, 1195 cm-1; R
f = 0.69 (20% EA/Hex). Spectral details previously reported
show a similar coupling of the expected product and since previously report spectra was collect in CCl4 on a 1HNMR (60 MHz) it shows the expected downfield shifts.24
Procedure for dialkyl peroxides via Alkylation with triflate: 2-((3-
Bromopropyl)peroxy)tetrahydro-2H-pyran and 2-((3-Iodopropyl)peroxy)tetrahydro- 2H-pyran.
A solution of alcohol (3.0 mmol, 1.0 equiv) in CH2Cl2 (0.3 M, 9 mL) was cooled to 0C,
and Tf2O (6.3 mmol, 2.1 equiv) and 2-6-lutidine (6.0 mmol, 2.2 equiv) were sequentially
added. The reaction was allowed to stir for 20 minutes at 0C before being diluted with cold hexane (25 mL). The solution was then washed with 0.1 M aq. KHSO4 (10 mL) and
then the combined organic layers were dried over sodium sulfate. The solution was then concentrated on a rotary evaporator (200 mmHg, 10C bath) to yield a light brown oil of crude triflate residue, which was stored in a -20C freezer, while a solution of alkyl hydroperoxide (3.0 mmol, 1.0 equiv) and THF (0.2 M, 20 mL) solution was prepared and cooled to 0C. KOtBu (3.0 mmol, 1.0 equiv) was added to the solution, which was stirred stir for several minutes to achieve dissolution before adding triflate (described initially). Reaction was stirred at 0C for 15 minutes before being quenched with water (5 mL). The mixture was extracted with three portions of 10% EA/Hex and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on rotary evaporator and purified with silica chromatography using 10% EA/Hex.
2-((3-Bromopropyl)peroxy)tetrahydro-2H-pyran (4a) was prepared (0.0832 g, 43%) by a
procedure adapted from Kyasa et al25. Using the Procedure for dialkyl THP peroxides
via Alkylation with triflate (above), 3-bromo-1-propanol (0.417 g, 3.0 mmol) was
reacted with Tf2O (3.17 mL, 6.3 mmol) and 2,6-lutitdine (2.1217 g, 6.6 mmol) to furnish
crude bromopropyl triflate, which was then reacted with THP hydroperoxide (0.3543 g, 3.0 mmol) and KOtBu (0.3366 g, 3.0 mmol) to furnish a colorless oil 1H NMR (400 MHz,
CDCl3) 5.15 (m, 1H), 4.25 (t, 2H, J = 5.8 Hz), 4.02 (m, 1H), 3.65 (m, 1H), 3.54 (m, 3H),
2.24 (td, 2H, J = 6.1, 2.8 Hz,), 1.75-1.58 (overlapping peaks, 5H); 13C NMR (400 MHz,
CDCl3) 101.0 (C, 1H), 72.9 (C, 2H), 62.8 (C, 2H), 31.4 (C, 2H), 30.1 (C, 2H), 27.9 (C, 2H),
25.2 (C, 2H), 19.8 (C, 2H); IR (neat): 2869, 1724, 1440, 1104 cm-1; R
f = 0.63 (20% EA/Hex).
1-(tert-Butylperoxy)-3-iodopropane (4b) [101860-37-1] was prepared (0.6994 g, 68%)
by first dissolving 1-iodopropanol (4.0 mmol, 0.7439 g) in CH2Cl2 (1.25 M, 5 mL) and
cooled at 0C, while adding Tf2O (8.4 mmol, 2.3699 g) dropwise for 10 minutes. Then
2,6-lutidine (8.8 mmol, 0.9430 g) was added and stirred for 20 minutes before diluting with cold hexane (10 mL) and 0.1 M KHSO4 (5 mL). Extract with a second portion of cold
hexane and then dried over sodium sulfate. Solvent was removed solvent on rotary evaporator at reduced temperature (10C). In a new flask, combine tBuOOH (4.0 mmol, 0.73 mL of 5.5 M solution in decane) was combined with THF (0.1 M, 10 mL) and stirred at 0C. Then KOtBu (4.8 mmol, 0.5386 g) was added and stirred until dissolved. Combine THF (0.1 M, 10 mL) and triflate intermediate and then added to tBuOOH/THF solution and stirred for 4 hours before quenching dropwise with water. The mixture was extracted with three portions of EA (3x50mL) and the combined organic layers were dried over sodium sulfate. Remove solvent on rotary evaporator and residue was purified by chromatography with 10% EA/Hex. A clear oil was isolated in 68% with Rf =
2-((3-Iodopropyl)peroxy)tetrahydro-2H-pyran (4c) was prepared (0.8252 g, 72%) by a
procedure adapted from Kyasa et al25. Using the Procedure for dialkyl THP peroxides
via Alkylation with triflate (above), 3-iodo-1-propanol (0.7439 g, 4.0 mmol) was reacted
with Tf2O (1.41 mL, 8.4 mmol) and 2,6-lutitdine (0.9430 g, 8.8 mmol) to furnish crude
iodopropyl triflate, which was then reacted with THP hydroperoxide (0.4725 g, 4.0 mmol) and KOtBu (0.4488 g, 4.0 mmol) to furnish a colorless oil with the following spectral details; 1H NMR (400 MHz, CDCl 3) 5.14 (m, 1H), 4.17 (t, 2H, J = 5.8 Hz), 4.00 (m, 1H), 3.64 (m, 1H), 3.29 (t, 2H, J = 6.8 Hz), 2.19 (quint, 2H, J = 6.4 Hz), 1.74-1.56 (overlapping peaks, 4H); 13C NMR (400 MHz, CDCl 3) 101.0 (C, 1H), 74.8 (C, 2H), 62.8 (C, 2H), 32.0 (C, 2H), 27.9 (C, 2H), 25.2 (C, 2H), 19.8 (C, 2H), 2.5 (C, 2H); IR (neat) 2940, 2869, 1439, 1351 cm-1; R f = 0.35 (10% EA/Hex).
2-((4-Iodobutyl)peroxy)tetrahydro-2H-pyran was prepared (0.3881 g, 43%) by an
adaptation of an existing procedure27. Cesium hydroxide (0.4497 g, 3.0 mmol) was
added to a flame dried flask in a glove bag under nitrogen atmosphere. DMF (5.3 mL, 0.56 M) was added to the cesium hydroxide and stirred at 0C for 2 hours to achieve dissolution. The THP hydroperoxide (0.4252 g, 3.6 mmol) was added, followed by 1,4- diiodobutane (0.9295 g, 3.0 mmol) in DMF (2.0 mL, 1.0M). The reaction was stirred for
15 hours at 25C and then quenched with water (~1.0mL). The aqueous layer was extracted with EA (12x10 mL) and the combined organic layers were dried over sodium sulfate. The solvent was removed on roto evaporator and then chromatographed with a 5-10% EA/Hex gradient to obtain a clear colorless oil with the following spectral details;
1H NMR (400 MHz, CDCl 3) 5.14 (m, 1H), 4.14 (t, 2H, J = 6.2 Hz), 4.01 (tt, 1 H, J = 8.3, 3.1 Hz), 3.65 (m, 1H), 3.24 (t, 2H, J = 6.9 Hz), 1.95 (quint, 2H, J = 6.9 Hz), 1.76 (m, 4H), 1.58 (m, 4H); 13C NMR (400 MHz, CDCl 3) 101.1 (C, 1H), 74.0 (C, 2H), 62.7 (C, 2H), 30.1 (C, 2H), 29.0 (C, 2H), 28.0 (C, 2H), 25.2 (C, 2H), 19.8 (C, 2H); IR: 2940, 2869, 1724, 1440, 1104 cm-1; R f = 0.47 (20% EA/Hex).
General Bistriflate Method.
Tf2O (7.5 mmol) was added dropwise to CH2Cl2 (0.1 M, 5 mL) and cooled to 0C. In a
separate vial, pyridine (5.0 mmol) and diol (5.0 mmol) were combined. The pyridine/diol mixture was then added dropwise to Tf2O solution over a period of 20 minutes. The
reaction was stirred for 10 minutes before being quenched with water. The mixture was extracted with three portions of EA and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on a rotary evaporator to furnish a waxy grey solid.
Ethane-1,2-diyl bis(trifluoromethanesulfonate) (5a) [18928-34-2] was prepared (1.7721
mmol) was reacted with Tf2O (1.84 mL, 11.0 mmol) and pyridine (0.80 mL, 10.5 mmol)
to furnish a bright purple waxy solid with spectral details; 1H NMR (300 MHz, CDCl 3)
4.79 (s, 4H); 13C NMR (300 MHz, CDCl
3) 71.5 (2C, 4H); 19F NMR (400 MHz, CDCl3) -
74.2 (2C, 6F). Spectral details matched those previously reported.28,29
Propane-1,3-diyl bis(trifluoromethanesulfonate) (5b) [63256-90-6] was prepared
(1.4149 g, 83%) using the General Bistriflate Method (above), 1,3-propanediol (0.3805 g, 5.0 mmol) was reacted with Tf2O (1.84 mL, 11.0 mmol) and pyridine (0.80 mL, 10.5
mmol) to furnish a pink/brown waxy solid with the following spectral details; 1H NMR
(300 MHz, CDCl3) 4.69 (t, 4H, J = 5.8), 2.38 (quint, 2H, J = 5.8 Hz); 13C NMR (300 MHz,
CDCl3) 71.3 (2C, 4H), 29.3 (C, 2H); 19F NMR (300 MHz, CDCl3) -74.4 (6F); IR (neat)
3440, 2986, 1714, 1410, 1195, 1138 cm-1. Spectral details matched those previously
reported.29
Butane-1,4-diyl bis(trifluoromethanesulfonate) (5c) [18934-34-4] was prepared (3.2489
g, 91%) with the General Bistriflate Method (above), 1,4-butanediol (0.9012 g, 10.0 mmol) was reacted with Tf2O (1.61 mL, 20.0 mmol) and pyridine (3.52 mL, 21.0 mmol)
to furnish a purple/brown waxy solid with the following spectral details; 1H NMR (400
(2C, 4H), 25.4 (2C, 4H); 19F NMR (400 MHz, CDCl
3) -74.6 (C, 3F); IR (neat) 3450, 2990,
2952, 2345, 1639, 1406 cm-1; R
f = 0.47 (20% EA/Hex). Spectral details matched those
previously reported.30
Bis tert-Butyl Peroxide Method A:
tBuOOH (0.18 mL, 1.0 mmol, of 5.5 M solution in decane) was added to THF (0.1 M, 10 mL) and cooled to 0C, followed by addition to KOtBu (0.1122 g, 1.0 mmol) and stirred until dissolution was achieved. Butane-1,4-diol bis(trifluoromethanesulfonate) (0.3542 g, 1.0 mmol) was added to the mixture and stirred for 2 hours and 15 minutes before being quenched dropwise with water. The mixture was extracted with three portions of 10% EA/Hex (3x30 mL) and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on a rotary evaporator and purified with silica chromatography using 5%-10% EA/Hex solvent gradient to obtain a clear colorless oil (0.0748 g, 32%).
Bis tert-Butyl Peroxide Method B.
tBuOOH (0.36 mL, 2.5 mmol, of 5.5 M solution in decane) was added to THF (0.1 M, 25 mL) and cooled to 0C, followed by addition to KOtBu (0.2524 g, 2.5 mmol) until
dissolution was achieved. Butane-1,4-diyl bis(trifluoromethanesulfonate) (0.8855 g, 2.5 mmol) was added and stirred for 20 minutes before being quenched dropwise with water. The mixture was extracted with three portions of EA (3x30 mL). The resulting solution was concentrated on the rotary evaporator and purified by silica
chromatography using a 5%-10% EA/Hex solvent gradient to obtain a clear colorless oil (0.1985 g, 34%).
1,4-bis(tert-Butylperoxy)butane (6a) [1071-33-6] was synthesized using Bis tert-butyl
peroxide method A and Bis tert-butyl peroxide method B as a clear colorless oil with the
following spectral details; 1H NMR (400 MHz, CDCl
3) 3.97 (t, 4H, J = 5.4 Hz), 1.69 (quint, 4H, J = 2.9 Hz), 1.25, (s, 18H); 13C NMR (400 MHz, CDCl 3) 80.2 (2C), 74.7 (2C, 4H), 26.4 (6C, 18H), 24.8 (2C, 4H); IR (neat) 2977, 2926, 2872, 1458, 1384, 1361, 1195 cm-1; R f = 0.78 (20% EA/Hex).
2-Hydroxyethyl trifluoromethanesulfonate (7a) [108286-01-7] was prepared (0.2263 g,
23%) using the Triflate Method, by reaction of ethylene glycol (0.3103 g, 5.0 mmol), pyridine (0.40 mL, 5.0 mmol) and Tf2O (0.84 mL, 5.0 mmol). Residue was purified by
silica chromatography with 100% DCM, followed by elution with 2% Methanol/DCM to furnish a viscous clear colorless oil with the following spectral details; 1H NMR (300
MHz, CDCl3) 4.63 (t, 2H, J = 3.9 Hz), 3.99 (t, 2H, J = 3.9 Hz), 2.47 (s, 1H); 13C NMR (300
MHz, CDCl3) 77.6 (C), 71.5 (C, 2H), 60.4 (C, 2H); 19F NMR (300 MHz, CDCl3) -74.5 (3F);
(3-(tert-Butylperoxy)prop-1-en-1-yl)benzene (8a) [101267-46-3] was prepared (0.2978
g, 48%) by addition of tBuOOH (3.0 mmol, 0.65 mL of a 5.5 M in decane solution) followed by cinnamyl bromide (3.0 mmol, 0.44 mL) to methanol (7.5 M, 0.4 mL) and stir at 0C for 10 minutes. In a separate via, KOH (3.0 mmol, 0.1683 g) was added to
methanol (2.5 M, 1.2 mL) and stirred until dissolution was achieved. KOH/methanol solution was added dropwise for 20 minutes to flask containing tBuOOH and cinnamyl bromide and then stirred for 2 days at 25C and then quenched with acidified water (pH 3). The mixture was extracted with three portions of EA and then the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on rotary evaporator and purified with 5% EA/Hex to afford a clear colorless oil (0.3069 g, 25%) of (8a) and (0.3214 g, 36%) of (3-Methoxyprop-1-en-1-yl)benzene.
(3-(tert-Butylperoxy)prop-1-en-1-yl)benzene (8a) [101267-46-3]. Clear colorless oi; 1H
NMR (400 MHz, CDCl3) 7.45 (d, 2H, J = 7.5 Hz), 7.36 (t, 2H, J = 7.2 Hz), 7.3-7.2
(overlapping peaks, 1 H), 6.66 (d, 1H, J = 15.9 Hz), 6.35 (dt, 1H, J = 16.0, 6.3 Hz), 1.28 (s, 9H); 13C NMR (400 MHz, CDCl
3) 133.8 (C), 128.5 (C, 1H), 128.3 (2C, 2H), 127.8 (2C, 2H),
126.4 (1C, 1H), 124.1 (C, 1H), 80.1 (C), 75.6 (C, 2H), 26.0 (3C, 9H); Rf = 0.69 (20%
EA/Hex). Spectral details matched those previously reported.31
HRMS submitted: calcd for 2-49F2 is C13H18O2
(3-Methoxyprop-1-en-1-yl)benzene (12) [16277-67-1]. Clear colorless oil; 1H NMR (400
(d, 1H, J = 16.1 Hz), 6.29 (td, 1H, J = 15.9, 5.8 Hz), 4.06 (d, 2H, J = 6.0 Hz), 3.35 (s, 3H); Rf
= 0.58 (20% EA/Hex). Spectral details matched those previously reported.32
(3-(tert-Butylperoxy)prop-1-en-1-yl)benzene (8a) [101267-46-3] (0.1921 g, 23%) was
prepared by an adapted procedure27. Cesium hydroxide (0.7195 g, 4.8 mmol) was
added to a flame dried flask in a glove bag under nitrogen atmosphere. DMF (20 mL, 0.2 M) was added to the cesium hydroxide and stirred at 0C for 20 minutes until dissolved. tBuOOH (0.72 mL, 4.0 mmol, of 5.5 M in decane) was added, followed by cinnamyl bromide (0.7882 g, 4.0 mmol) in DMF (10 mL, 0.4 M) and stirred for 10 minutes at 0C before being quenched with water (5mL) and then diluted with EA (20 mL) and washed with aq. brine (150 mL) to remove DMF. The mixture was extracted with two portions of EA (2x20mL) and then combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on rotary evaporator and purified with silica chromatography using 5% diethyl ether/Hex to furnish a clear colorless oil, with a faint cinnamon odor. Spectral details matched those previously reported.31
3-(tert-Butylperoxy)prop-1-ene (8b) [39972-78-6] was prepared (1.1220 g, 86%) by an
adaption of an existing procedure by Mosher et al.18 tBuOOH (10 mmol, 1.80 mL of 5.5
methanol (9.0 M, 1.1 mL) and then stirred at -5C for a period of 10 minutes. In a separate vial, KOH (12 mmol, 0.6732 g) was added to methanol (2.9 M, 4.1 mL) and stirred until dissolution was achieved. The mixture was then added to a flask containing tBuOOH and allylbromide and stirred for a period of 20 minutes before being quenching with acidified water (pH 3) after 4 hours. The mixture was then extracted with two portions of pentane (2x30 mL) and the combined organic layers were dried over sodium sulfate. The resulting solution was concentrated on a rotary evaporator at reduced temperature (10C and 200 mmHg) to furnish a clear colorless liquid with a strong burnt rubber/pentane odor (1.1220 g, 86%) 1H NMR (300 MHz, CDCl
3) 5.96 (ddd, 1H, J = 6.1,
10.3, 12.2 Hz), 5.31 (dq, 1H, J = 17.3, 1.4 Hz), 5.20 (d, 1H, J = 10.3 Hz), 4.44 (dt, 2H, J = 6.1, 1.1 Hz), 1.26 (s, 9H); Rf = 0.78 (20% EA/Hex). Previously reported spectra by Baj et al
does not match expected vinyl splitting, clearly shown by the spectra reported here.33
1-Methyl-1-phenylethyl 2-propen-1-yl peroxide (8c) [61808-93-3] was prepared
(0.6093 g, 83%) by addition of Cumyl hydroperoxide (1.2175 g, 8 mmol) to the flask, followed by allyl bromide (0.9678 g, 8 mmol) with methanol (8.0 M, 1.0 mL) and cooled to -5C (ice/brine bath). In a separate flame dried vial, KOH (0.4936 g, 8 mmol) and methanol (3.2 mL) were combined and stirred until dissolution was achieved. The mixture of potassium hydroxide and methanol was added dropwise to the flask containing the peroxide and allyl bromide. The reaction was warmed to room
temperature and stirred for 18 hours before dropwise addition of acidified water (aq. HCl pH 3) while cooling at 0C. The organic layer was separated and the aqueous layer was washed with three portions (3x25 mL) of hexane. The combined organic layers were dried over sodium sulfate and then concentrated with a rotary evaporator. The residue was purified by silica chromatography with 10% EA/Hex to furnish clear colorless oil with a slight burnt rubber odor with the following spectral details; 1H NMR (300 MHz,
CDCl3) 7.50 (d, 2H, J = 7.7 Hz), 7.36 (t, 2H, J = 7.7 Hz), 7.30-7.25 (overlapping peaks,
1H), 5.93 (dq, 1H, J = 17.2, 6.0 Hz), 5.25 (2H, Jtrans = 10.6, Jcis = 18.9 Hz), 4.42 (d, 2H, J =
5.9 Hz), 1.62 (s, 6H), 13C NMR (400 MHz, CDCl
3) 145.4 (C), 133.2 (C, 1H) 128.1 (2C, 2H),
127.2 (C, 1H), 125.6 (2C, 2H), 118.9 (C, 2H), 83.0 (C), 76.2 (1C, 2H), 26.6 (2C, 6H), Rf =
0.73 (20% EA/Hex). Spectral details previously reported.33
Triflate Method.
The alcohol (1.0 equiv) was added to CH2Cl (0.1 M) and cooled to 0C, before pyridine
(2.2 equiv) and Tf2O (2.1 equiv) were added sequentially. The reaction was warmed to
25C and then stirred for 15-20 minutes before being quenched dropwise with water. The mixture was extracted with three portions of Hex and then the combined organic layers were dried over sodium sulfate. The solution was concentrated on a rotary evaporator to furnish a residue which was diluted with Hex and washed with three portions (3x10 mL) of 0.1M H2SO4. The combined organic layers were dried over sodium
sulfate and then concentrated on a rotary evaporator to furnish triflate product without further purification.
2-(tert-Butylperoxy)ethan-1-ol (9a) [15476-85-4] was prepared (0.0693 g, 26%) by
addition of 3-(tert-butylperoxy)prop-1-ene (0.2603 g, 2.0 mmol) to methanol (0.2 M, 10 mL) and cooled to -41C (dry ice/acetonitrile bath). Was stirred while a stream of O3/O2
was introduced through a glass pipet directly over the surface for 3 min, or until TLC showed no more starting material. Solution was warmed solution to 0C and then sodium borohydride (0.3026 g, 8.0 mmol) was added slowly over 20 minutes. Reaction was quenched dropwise with water after 30 minutes and then the mixture was washed with one portion of pentane. Product was extracted product from pentane wash with 50% methanol/water (20 mL), followed by extraction with five portions (5x10 mL) of EA. The combined EA/Methanol organic layers were combined and then dried over sodium sulfate. The solvent was removed on a rotary evaporator to furnish a viscous clear colorless oil with the following spectral details; 1H NMR (300 MHz, CDCl
3) 4.08 (m,
2H), 3.84 (m, 2H), 2.09 (t, 1H, J = 5.5 Hz), 1.27 (s, 9H), Rf = 0.23 (20% EA/Hex). To obtain
a 1H NMR spectrum in CDCl
3, product, D2O was added to the sample to clearly see
coupling of the alcohol proton. Spectral details match those previously reported.34
2-[(1-Methyl-1-phenylethyl)dioxy]-ethanol (9b) [54635-44-8] was prepared (0.3300g,
mL) and methanol (0.8 M, 15.0 mL) and cooled to -78C (dry ice/acetone bath). Stir while a stream of O3/O2 was introduced through a glass pipet directly over the surface
for 30 min, or until TLC showed no more starting material. Solution was warmed solution to 0C and then sodium borohydride (0.9419 g, 24.9 mmol) was added slowly over 20 minutes. Reaction was quenched dropwise with water after 30 minutes. The mixture was extracted with three portions of EA and the combined organic layers were dried over sodium sulfate. The solvent was removed on a rotary evaporator and the residue was purified by silica chromatography with a 5-20% solvent gradient to furnish a clear colorless oid with the following spectral details; 1H NMR (400 MHz, CDCl
3) 7.51
(d, 2H, J = 8.1 Hz), 7.38 (t, 2H, J = 7.4 Hz), 7.30 (t, 1H, J = 7.0 Hz), 4.05 (dt, 2H, J = -2.1, 4.4), 3.79 (m, 2H), 1.87 (t, 1H, J = 6.4 Hz), 1.64 (s, 6H), HRMS submitted: calcd for 4-32F3 is C11H16O3. Spectral details matched previously reported.35,34,36
2-(tert-Butylperoxy)ethyl trifluoromethanesulfonate (10a) was prepared (0.0350 g 44)
by following the General Triflate Method by the reaction of 2-(tert-Butylperoxy)ethan-
1-ol (0.0402 g, 3.0 mmol) with Tf2O (0.06 mL, 3.6 mmol) and pyridine (0.02 mL, 3.0 mmol) to furnish a light brown oil with the following spectral details; 1H NMR (300 MHz,
CDCl3) 4.72 (t, 2H, J = 4.3 Hz), 4.23 (t, 2H, J = 4.3 Hz), 1.26 (s, 9H), Rf = 0.61 (20%
2-((2-Phenylpropan-2-yl)peroxy)ethyl trifluoromethanesulfonate (10b) was prepared
(0.6771 g, 90%) by Triflate Method by reaction of (9b) (0.6440 g, 3.5 mmol) with Tf2O
(1.29 mL, 7.7 mmol) and 2,6-lutidine (0.85 mL, 7.35 mmol) to furnish a light red/brown oil with the following spectral details; 1H NMR (300 MHz, CDCl
3) 7.48 (d, 2H, J = 7.2 Hz), 7.38 (t, 2H, J = 7.7 Hz), 7.30 (t, 1H, J = 6.6), 4.72 (t, 2H, J = 4.6 Hz), 4.21 (t, 2H, J = 4.6 Hz), 1.63 (s, 6H), 13C NMR (400 MHz, CDCl 3) 144.6 (C, 1H), 128.2 (2C, 2H), 127.5 (2C, 2H), 125.5 (C), 83.7 (C) 73.4 (C, 2H), 71.7 (C, 2H), 26.4 (2C, 6H), 19F NMR (400 MHz, CDCl3) -74.6 (C, 3F), Rf = 0.53 (20% EA/Hex).
(2-((2-Iodoethyl)peroxy)propan-2-yl)benzene (11b) was prepared (0.5907 g, 96%) by
mixing sodium iodide (1.4989 g, 10.0 mmol) in acetone (40.0 mL, 0.05 M) and then adding 2-((2-Phenylpropan-2-yl)peroxy)ethyl trifluoromethanesulfonate (0.6566 g, 2.0 mmol) and stirring at 48C for 30 minutes before adding water (~10 mL) and extracting with hexane (3x20 mL). The combined organic layers were dried over sodium sulfate and removed solvent on rotary evaporator to obtain a slightly yellow clear oil in 96%. 1H