反应详情

A solution of 2-methylene-3-phenyloxetane (0.10 g, 0.69 mmol) in dry CH2Cl2 (˜0.5 M) was cooled to −78° C. A solution of DMDO (˜0.35 M in CH2Cl2, 1.0-1.2 equiv) was added dropwise with stirring. The reaction mixture was stirred at −78° C. for 1 hour after which the solvent was removed in vacuo to give 3-phenyl-1,5-dioxaspiro[3.2]hexane as a colorless oil (0.11 g, 99%) and as a mixture of diastereomers (93:7). Major diastereomer: 1H NMR (400 MHz, CDCl3) δ 7.33 (m, 5H), 4.85 (m, 1H), 4.49 (m, 2H), 2.93 (d, J=3.4 Hz, 1H), 2.54 (d, J=3.4 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 136.6, 128.9, 127.8, 127.5, 95.0, 70.1, 50.5, 47.9. Minor diastereomer: 1H NMR (400 MHz, CDCl3) δ 7.33 (m, 5H), 4.85 (m, 1H), 4.65 (app t, J=6.6 Hz, 1H), 4.58 (dd, J=6.3, 5.0 Hz, 1H), 3.06 (d, J=3.4 Hz, 1H), 2.76 (d, J=3.4 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 135.5, 129.3, 128.6, 128.2, 92.7, 72.0, 51.4, 46.7; HRMS (FAB) calculated for C10H11O2 (M++1) m/z: 163.0759. Found: 163.0762.

1. stirringThe reaction mixture was stirred at −78° C. for 1 hour after which the solvent
2. customwas removed in vacuo