反应详情

To a solution of 4.46 g (9.6 mmole) of [(2R)-8-allyl-7-(benzyloxy)-2,3-dihydro-1,4-bezodioxin-2-yl]methyl 4-methylbenzenesulfonate in 30 mL of tetrahydrofuran at −10° C. was added 21 mL (21 mmole) of 1 M borane/tetra-hydrofuran. The solution was allowed to come to room temperature and stir under nitrogen for 3 days. Saturated aqueous sodium bicarbonate (50 mL) was cautiously added, followed by 2.5 mL of 30% hydrogen peroxide. The mixture was stirred at room temperature under nitrogen for 2 hours, then it was extracted with three 60 mL portions of ether. The combined extracts were dried over magnesium sulfate, filtered and concentrated in vacuum to give 4.87 g of the (R)-enantiomer of the title compound as a colorless oil. 1H-NMR (CDCl3): doublet 7.8 δ (2H); multiplet 7.4 δ (5H); doublet 7.35 δ (2H); doublet 6.65 δ (1H); doublet 6.45 δ (1H); singlet 5.0 δ (2H); multiplet 4.45 δ (1H); multiplet 4.2 δ (3H); doublet of doublets 4.0 δ (1H); triplet 3.5 δ (2H); doublet of triplets 2.73 δ (2H); singlet 2.45 δ (3H); multiplet 1.75 δ (2H).

1. customto come to room temperature
2. stirringThe mixture was stirred at room temperature under nitrogen for 2 hours
3. extractionit was extracted with three 60 mL portions of ether
4. dry with materialThe combined extracts were dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuum