REACTIONS OF THEBAINE AND 6-DEMETHOXYTHEBAINE ANIONS WITH CARBONYL-COMPOUNDS - NOVEL DIELS-ALDER ADDUCTS FROM 5-BETA-SUBSTITUTED THEBAINES (CHEMISTRY OF OPIUM-ALKALOIDS, .39.

Reaction of the anions of thebaine and 6-demethoxythebaine with 2-prop anone gave the 5beta-(dimethylmethanol)-substituted analogues 3 and 5 and the isomeric C-7-substituted morphinan-5,8-dienes 4, 6 and 7, resp ectively. No reaction took place with methanal. Therefore, thebaine-5b eta-methanol (10) was prepared by reacting the anion with alkyl chloro formate followed by lithium aluminium hydride reduction. Diels-Alder r eaction of diene 10 with ethyl acrylate gave the 6alpha,14alpha-etheno isomorphinan 11. Of the morphinan-6,8-dienes 3 and 5, only diene 5 sho wed a reaction, namely rearrangement followed by cycloaddition with et hyl acrylate, yielding three adducts. The structure of the major adduc t 13 was elucidated using 1D- and 2D-NMR techniques and revealed an ap orphine-like structure. Furthermore, the conversion of 11 into a new e torphine analogue 16 was accomplished by treatment with methylmagnesiu m bromide followed by 3-O-demethylation.