Asymmetric cyclization–carbonylation of 2-alkyl-2-propargylcyclohexane-1,3-diones: facile access to optically active hydrindanes
摘要:
Oxidative cyclization - carbonylation of 2-alkyl-2-propargylcyclohexane-1,3-diones mediated by Pd(TFA)(2)/2,2'-isopropylidenebis[(4R)4-(3,4-dimethoxyphenyl)-2-oxazoline] 28 afforded bicyclic-beta-alkoxyacrylates in 51 - 74% yields with 72 - 82% ee. The products containing quaternary carbon were converted to optically active hydrindanes 33. (c) 2007 Elsevier Ltd. All rights reserved.