格氏试剂还原樟脑的立体选择性研究

Study on Stereoselectivety of Reduction of Camphor Using Grignard Reagent

天然樟脑与-βC上有活泼氢的格氏试剂反应时,由于樟脑分子外侧空阻大于内侧空阻,格氏试剂立体选择性地主要从空阻小的内侧进攻羰基,发生加氢反应,得到以外型为主的冰片(异冰片).

When natural camphor reacted to Grignard reagent with active hydrogen in the β-carbon,because exosteric barrier of molecule of camphor is larger than endo-steric barrier, the carbonyl group of camphor was stereoselectively attacked from endo by Grignard reagent and then the hydrogenation happened. The excess exoborneol（iso-borneol） was obtained.