关键词: 取代反应, 醛, 有机硅化合物, 硅烷 P, 昆虫激素, 烯丙基, 手征性, 蒎烯, 亲电反应, 不对称反应

The chiral allylsilane I was prepared from (-)-b-pinene and was assigned to have 1S, 2S, 5S stereochem. The reactions of I with a no. of aldehydes were found to give chiral homoallylic alcs. with modest enantioselectivity. More importantly, enantioselectivity was found to be dependent on the Lewis acid used. With TiCl4, the absolute configuration of the chiral homoallylic alcohol is consistently R, on the other hand with SnCl4 or BF3-OEt2 oppositely S. The reaction was used to synthesize optically active 4-octyl-g-butyrolactone (II).

Key words: SUBSTITUTION REACTION, ALDEHYDES, ORGANO SILICON COMPOUNDS, SILANE P, INSECT HORMONE, ALLYL GROUP, CHIRALITY, PINENE, ELECTROPHILIC REACTION