Stereoselective desymmetrization of 4-pyridone has been achieved through selective N-galactosylation, activation of the N-(galactosyl)pyridone by O-silylation and immediate addition of Grignard compounds. Chiral piperidine derivatives, e.g. (S)-(+)-coniine and (5S,9S)-(+)-indolozidine 167B, were synthesised in enantiomericallypure form using these highly regio- and stereoselective reactions. After
Desymmetrization Reactions on 4-Pyridone Using Carbohydrate Templates
作者:Markus Follmann、Horst Kunz
DOI:10.1055/s-1998-3139
日期:1998.9
After activating O-silylation, O-pivaloylated N-d-galactopyranosylpyrid-4-ones and N-l-arabinopyranosylpyrid-4-ones react with Grignard reagents to give 2-substituted 5,6-dehydropiperid-4-ones with good to high diastereoselectivity.