Structure of a Diels–Alder adduct at a 5,7-disubstituted thebaine derivative
作者:R. H. Woudenberg、H. van Koningsveld、L. Maat
DOI:10.1107/s0108270193010777
日期:1994.6.15
The structure of (+)-ethyl 3,18-dimethoxy-5beta,17-dimethyl-4,5alpha-epoxy-6beta,14beta-ethenomorphinan-8beta-carboxylate (3), C25H31NO5, is described. Diels-Alder reaction of the thebaine analogoue (-)-5beta-methyl-7-methoxy-6-demethoxythebaine (2), with ethyl propenoate gives rise to anomalous alpha-face approach of the dienophile, yielding the title compound (3), in which the etheno bridge is at the 6beta,14beta position and the ethoxycarbonyl substituent is at the 8beta position.