[1+2]Cycloaddition to thebaine alcaloid under catalysis by copper triflate of carbene generated from CH(2)N(2) occurred stereoselectively affording 6beta,7beta-methylene-6,7-dihydrothebaine. The simultaneously proceeding 8beta,14beta-cyclopropanation and nitrogen quaternization furnished N,N-dimethyl-N-nor-8beta,14beta-methylene-8,14-dihydrothebaine triflate whose structure was established by X-ray diffraction analysis. The possibility of preparation of 14beta-hydroxy-6beta,7beta-methylene-8alpha-substituted dihydrocodeine derivatives was demonstrated.
[1+2]Cycloaddition to thebaine alcaloid under catalysis by copper triflate of carbene generated from CH(2)N(2) occurred stereoselectively affording 6beta,7beta-methylene-6,7-dihydrothebaine. The simultaneously proceeding 8beta,14beta-cyclopropanation and nitrogen quaternization furnished N,N-dimethyl-N-nor-8beta,14beta-methylene-8,14-dihydrothebaine triflate whose structure was established by X-ray diffraction analysis. The possibility of preparation of 14beta-hydroxy-6beta,7beta-methylene-8alpha-substituted dihydrocodeine derivatives was demonstrated.