摘要:
[GRAPHICS]Simple Grignard procedures provide methallylboranes la and 1b in enantiomerically pure form from air-stable precursors in 98% and 95% yields, respectively. These reagents add smoothly to aldehydes and methyl ketones, respectively, providing branched 2 degrees- (6, 69-89%, 94-99% ee) and 3 degrees-(10, 71-87%, 74-96% ee) homoallylic alcohols.