ChemInform Abstract: ACTION OF BORON TRIFLUORIDE ON AROMATIC ACETALS

Hypervalent (tert-Butylperoxy)iodanes Generate Iodine-Centered Radicals at Room Temperature in Solution: Oxidation and Deprotection of Benzyl and Allyl Ethers, and Evidence for Generation of α-Oxy Carbon Radicals

“…Other benzyl ethers were prepared by the reaction of sodium alkoxides with benzyl bromide in the presence of tetrabutylammonium iodide . Benzyl ethers prepared by this way and their 1 H NMR are as follows: benzyl ethyl ether ( 2b ), δ 7.35−7.28 (m, 5H), 4.50 (s, 2 H), 3.53 (q, J = 6.4 Hz, 2 H), 1.24 (t, J = 6.4 Hz, 3 H); benzyl 2-propyl ether ( 2c ), δ 7.34−7.28 (m, 5 H), 4.50 (s, 2 H), 3.67 (sept, J = 6.1 Hz, 1 H), 1.21 (d, J = 6.1 Hz, 6 H); benzyl n -butyl ether ( 2d ),9d δ 7.33 (m, 5 H), 4.50 (s, 2 H), 3.47 (t, J = 6.5 Hz, 2 H), 1.67−1.31 (m, 4 H), 0.92 (t, J = 7.3 Hz, 3 H); benzyl 2-butyl ether ( 2e ), δ 7.33 (m, 5 H), 4.56 (d, J = 11.7 Hz, 1 H), 4.46 (d, J = 11.7 Hz, 1 H), 3.44 (sext, J = 6.1 Hz, 1 H), 1.81−1.43 (m, 2 H), 1.18 (d, J = 6.1 Hz, 3 H), 0.93 (t, J = 6.4 Hz, 3 H); benzyl tert -butyl ether ( 2f ), 9a, δ 7.40−7.20 (m, 5 H), 4.45 (s, 2 H), 1.29 (s, 9 H); benzyl cyclopentyl ether ( 2g ),9b δ 7.31 (m, 5 H), 4.47 (s, 2 H), 4.06−3.88 (m, 1 H), 1.80−1.39 (m, 8 H); benzyl cyclohexyl ether ( 2h ), 9a, δ 7.30 (m, 5 H), 4.53 (s, 2 H), 3.43−3.24 (m, 1 H), 2.00−1.17 (m, 10 H); benzyl 1-methylcyclohexyl ether ( 2i ), δ 7.40−7.21 (m, 5 H), 4.41 (s, 2 H), 1.90−1.20 (m, 10 H), 1.22 (s, 3 H); benzyl menthyl ether ( 2j ),9c δ 7.33 (m, 5 H), 4.66 (d, J = 11.5 Hz, 1 H), 4.39 (d, J = 11.5 Hz, 1 H), 3.17 (dt, J = 4.2, 10.5 Hz, 1 H), 2.43−2.12 (m, 2 H), 1.80−0.90 (m, 7 H), 0.93 (d, J = 7.3 Hz, 3 H), 0.90 (d, J = 7.3 Hz, 3 H), 0.70 (d, J = 6.8 Hz, 3 H); benzyl cis -4- tert -butylcyclohexyl ether ( 2k ), δ 7.40−7.18 (m, 5 H), 4.50 (s, 2 H), 3.68−3.56 (m, 1 H), 2.08−1.92 (m, 2 H), 1.60−1.20 (m, 7 H), 0.86 (s, 9 H); benzyl trans -4- tert -butylcyclohexyl ether ( 21 ), δ 7.40−7.17 (m, 5 H), 4.55 (s, 2 H), 3.25 (tt, J = 11.0, 4.4 Hz, 1 H), 2.20−2.04 (m, 2 H), 1.87−1.72 (m, 2 H), 1.40−0.90 (m, 5 H), 0.84 (s, 9 H); benzyl cis -2-methylcyclohexyl ether ( 2m ), δ 7.46−7.18 (m, 5 H), 4.58 (d, J = 12.2 Hz, 1 H), 4.43 (d, J = 12.2 Hz, 1 H), 3.44 (dt, J = 6.1, 3.0 Hz, 1 H), 1.97−1.12 (m, 9 H), 0.97 (d, J = 7.1 Hz, 3 H); benzyl trans -2-methylcyclohexyl ether ( 2n ), δ 7.46−7.18 (m, 5 H), 4.64 (d, J = 11.7 Hz, 1 H), 4.43 (d, J = 11.7 Hz, 1 H), 2.90 (dt, J = 4.5, 9.5 Hz, 1 H), 2.30−2.00 (m, 1 H), 1.89−1.09 (m, 8 H), 1.02 (d, J = 6.4 Hz, 3 H); benzyl phenyl ether ( 2o ), 9a, δ 7.47−7.19 (m, 7 H), 7.00−6.88 (3 H), 5.04 (s, 2 H); n -butyl p -methoxybenzyl ether ( 2p ), δ 7.25 (dt, J = 8.5, 2.2 Hz, 2 H), 6.86 (dt, J = 8.5, 2.2 Hz, 2 H), 4.42 (s, 2 H), 3.79 (s, 3 H), 3.44 (t, J = 6.5 Hz, 2 H), 1.64−1.30 (m, 4 H), 0.91 (t, J = 7.2 Hz, 3 H); n -butyl p -methylbenzyl ether ( 2q ), δ 7.22 (d, J = 8.1 Hz, 2 H), 7.13 (d, J = 8.1 Hz, 2 H), 4.46 (s, 2 H), 3.45 (t, J = 6.6 Hz, 2 H), 2.33 (s, 3 H), 1.66−1.25 (m, 4 H), 0.91 (t, J = 7.1 Hz, 3 H); n -butyl p -chlorobenzyl ether ( 2r ), δ 7.28 (m, 4 H), 4.45 (s, 2 H), 3.46 (t, J = 6.5 Hz, 2 H), 1.63−1.37 (m, 4 H), 0.92 (t, J = 7.2 Hz, 3 H); n -butyl m -clorobenzyl ether ( 2s ), δ 7.33 (br s, 1 H), 7.25 (m, 3 H), 4.46 (s, 2 H), 3.47 (t, J = 6.3 Hz, 2 H), 1.67−1.22 (m, 4 H), 0.92 (t, J = 7.6 Hz, 3 H); n -butyl p -phenylbenzyl ether ( 2t ), δ 7.66−7.50 (m, 4 H), 7.50−7.26 (m, 5 H), 4.52 (s, 2 H), 3.49 (t, J = 6.5 Hz, 2 H), 1.69−1....…”

“…The solution was dried over anhydrous Na 2SO4 and concentrated. Flash chromatography of the crude product mixture yielded 2x (264 mg, 62%): colorless oil; 1 H NMR δ 7.32 (m, 5 H), 4.57 (m, 1 H), 4.50 (s, 2 H), 4.00-3.68 (m, 2 H), 3.60-3.28 (m, 4 H), 1.96-1.28 (m, 11 H), 0.92 (d, J ) 6.4 Hz, 3 H); MS m/z (rel intensity) 207 (11, M + -C5H9O), 191 (9), 185 (7), 105 (100), 101 (72), 83 (67), 67 (34), 55 (73); HRMS, calcd for C 13H19O2 (M + -C5H9O) 207.1385, found 207.1372.…”

“…Concentration in vacuo gave an oil, which was purified by preparative TLC to give n-butyl benzoate (3d) (18.8 mg, 55%) and the TEMPO adduct 28 (18 mg, 28%). 28: colorless oil; IR (film) 2900, 2850, 1430, 1355, 1340, 1110, 1060, 1000, 960, 940, 680 cm -1 ; 1 H NMR δ 7.60-7.24 (m, 5 H), 5.72 (s, 1 H), 3.54-3.30 (m, 2 H), 1.80-0.90 (m, 10 H), 1.35 (s, 3 H), 1.17 (s, 3 H), 1.12 (s, 3 H), 1.00 (s, 3 H), 0.84 (t, J ) 7.2 Hz, 3 H); FABMS m/z (rel intensity) 320 (3, M + -1), 163 (100), 140 (72), 107 (100), 79 (8), 57 (10); HRFABMS, calcd for C 20H33NO2 (M + ) 319.2511, found 319.2466.…”