反应详情

A particularly preferred embodiment of the present invention is the use of the borohydrides described herein for the hydrogenation of ketones. Thus, the present compounds further react with ketones to give a predominance of one isomer. For example, lithium perhydro-9b-boraphenalylhydride reacts with camphor to give a quantitative yield of 99% isoborneol. The same hydride reacts with 2-methyleyclopentanone to give cis-2-methylcyclopentanol of 94% epimeric purity. In contrast, sodium borohydride reduction of 2-methylcyclopentanone gives only 31% of the cis-epimer while lithium tri-n-butylborohydride, which has the same number of carbon atoms as the phenalyl compound but as three long alkyl groups attached to the boron, gives only 67% of the cis-epimer.

1. customto give a predominance of one isomer