Synthesis of 7-substituted 6-demethoxythebaines and Diels-Alder reaction of 7-methoxy-5β-methyl-6-demethoxythebaine (chemistry of opium alkaloids, part XLI)
作者:R. H. Woudenberg、G. J. Meuzelaar、L. Maat
DOI:10.1002/recl.19931121104
日期:——
methanol from 14 yielded the desired diene 15. Diels-Alderreaction of 15 with ethyl acrylate yielded exclusively the 8β-substituted 6β,14β-ethenomorphinan 16, due to α-face approach. Cycloaddition of diene 15 with maleic anhydride gave the 6α, 14α-ethenoisomorphinan 17 and the 6β,14β-ethenomorphinan 18 in a ratio of 5: 4. The outcome of the Diels-Alderreactions is discussed in relation to the substituents
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.