反应详情

The resultant product of Example 1 (2.80 g, 9.88 mmol) in dry dimethylformamide (DMF) (50 ml) was added to a stirred suspension of NaH (593 mg of a 60% dispersion in oil, 14.8 mmol, hexane washed) in dry DMF (50 ml). After 3 h, the mixture was quenched (750 ml water+100 ml brine) and extracted with ether (5×100 ml). The combined organic phase was washed with brine (3×50 ml), dried (MgSO4), filtered and evaporated to an oil (2.23 g). The NMR spectrum of the crude product revealed an 82:18 mixture of 5S:5R diastereomers. Silica gel chromatography gave 80% recovery of pure diastereomers. 5S:

1. washwashed) in dry DMF (50 ml)
2. customthe mixture was quenched (750 ml water+100 ml brine)
3. extractionextracted with ether (5×100 ml)
4. washThe combined organic phase was washed with brine (3×50 ml)
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. customevaporated to an oil (2.23 g)
8. additionan 82:18 mixture of 5S
9. customSilica gel chromatography gave 80% recovery of pure diastereomers