反应详情

The compound of step (e) (21 g) was dissolved in methanol (100 ml) and the solution cooled to 0° C. while sodium borohydride (1.5 g) was added portionwise over 15 minutes. When addition was complete, the solvent was removed in vacuo, water (100 ml) and chloroform (100 ml) added and the organic phase separated. After drying over anhy. sodium sulphate, filtration and concentration in vacuo gave the crude product as a brown gum (21 g). This was purified by column chromatography (silica, 10:1 diethyl ether:methanol) to give the desired product as fine white needles (7.5 g), mp 150.3°-150.8° C.

1. additionwas added portionwise over 15 minutes
2. additionWhen addition
3. customthe solvent was removed in vacuo, water (100 ml) and chloroform (100 ml)
4. additionadded
5. customthe organic phase separated
6. customAfter drying over anhy
7. filtrationsodium sulphate, filtration and concentration in vacuo
8. customgave the crude product as a brown gum (21 g)
9. customThis was purified by column chromatography (silica, 10:1 diethyl ether:methanol)