Improving the stereoselectivity of one-carbon atom homologation of hexoses at the terminal position
摘要:
A number of modifications of the original Grignard C-1 homologation of hexoses as examined, e.g. reactions of protected hexodialdo-1,5-pyranosides with benzyloxymethyllithium, transmetalation, precomplexation of the aldehydes. Some of the modifications, e.g. benzyloxymethyl Grignard addition in the presence of tert amines showed good to very good stereoselectivity of the heptoside formation. (C) 2002 Elsevier Science Ltd. All rights reserved.