反应详情

A solution of 980 mg. (S)-3-t-butoxycarbonylamino-(R)-2-benzyloxy-4-cyclohexylbutyric acid methyl ester (Ii) in dry toluene (5 ml.) was cooled and stirred at -78° C. while a solution of diisobutylaluminum hydride (DIBAL-H, 6.05 ml.) was added dropwise so that the temperature did not exceed -65° C. 15 minutes after completion of the DIBAL-H addition dry ethyl formate (0.48 ml.) was added dropwise followed by dry methanol (0.6 ml.), stirring being then continued another 15 minutes at -78° C. whereupon a 50% aqueous solution of Rochelle salts was added (10 ml.) followed by ether (50 ml.), and the mixture was brought to room temperature. The emulsion was allowed to separate and the ether layer was washed with brine, dried and concentrated to give 880 mg. (97%) of the title aldehyde which was used without further purification.

1. additionwas added dropwise so that the temperature
2. customdid not exceed -65° C
3. additionwas added dropwise
4. additionwas added (10 ml.)
5. customwas brought to room temperature
6. customto separate
7. washthe ether layer was washed with brine
8. customdried
9. concentrationconcentrated
10. customto give 880 mg
11. custom(97%) of the title aldehyde which was used without further purification