Dearomatising cyclisation of lithiated 1-naphthamides with a phenylglycinol-derived chiral auxiliary: asymmetric synthesis of an arylkainoid and a kainoid-like pyroglutamate
作者:Ryan A Bragg、Jonathan Clayden、Michael Bladon、Osamu Ichihara
DOI:10.1016/s0040-4039(01)00502-0
日期:2001.5
N-benzylphenylglycinols undergo a diastereoselective dearomatising cyclisation on treatment with t-BuLi and DMPU or HMPA. A new pyrrolidinone ring is formed bearing three new stereogenic centers of defined absolute stereochemistry. Removal of the phenylglycinol auxiliary gives enantiomerically pure substituted lactams exhibiting the stereochemistry of the kainoids. These may be converted to kainoid-like pyroglutamates
在用t -BuLi和DMPU或HMPA处理后,N-苄基苯基甘氨醇的1-萘酰胺经历非对映选择性脱芳环化。形成带有定义的绝对立体化学的三个新的立体异构中心的新的吡咯烷酮环。除去苯基甘氨醇助剂,得到对映体纯的取代内酰胺,其表现出类胡萝卜素的立体化学。这些可以被转化成类卡因碱样的焦谷氨酸盐,或者可替代地,使用先前论文的方法,被转化为丙烯醛酸的类似物。