tert-butyl N-(3-benzyl-2-oxooxolan-3-yl)carbamate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of tert-butyl (3-benzyl-2-oxotetrahydrofuran-3-yl)carbamate (4.18 g, 14.3 mmol) in THF (100 mL) cooled to −78° C. was added DIBAL-H (57.4 mL, 57.4 mL, 1M hexane) dropwise over 15 min. The reaction mixture was stirred at −78° C. for 5 h, quenched with EtOAc, diluted with diethyl ether and aqueous Rochelle's salt. Vigorous stirring was allowed until gel break-up and layer formation. The organic layer was extracted, washed with aqueous Rochelle's salt, water, brine, dried over sodium sulfate, concentrated in vacuo, and purified by flash chromatography (120 g silica gel, 0 to 40% EtOAc in hexane) to give tert-butyl (3-benzyl-2-hydroxytetrahydrofuran-3-yl)carbamate (intermediate I) as a white foam (ca. 1:1 diastereomeric ratio). 1H NMR (400 MHz, CDCl3) δ 7.35-7.12 (m, 5H), 5.35 (s, 0.5H), 5.32 (s, 0.5H), 5.97 (s, 0.5H), 4.25 (s, 0.5H), 4.20-4.08 (m, 1H), 4.00-3.86 (m, 1H), 3.48-2.88 (m, 3H), 2.28-1.84 (m, 2H), 1.49 (s, 4.5H), 1.47 (s, 4.5H). MS M+Na=316. quenched with EtOAc diluted with diethyl ether and aqueous Rochelle's salt Vigorous stirring The organic layer was extracted washed with aqueous Rochelle's salt, water, brine dried over sodium sulfate concentrated in vacuo purified by flash chromatography (120 g silica gel, 0 to 40% EtOAc in hexane)