The synthesis of some 6,7-annulated codeines

Abstract

A benzofuro[6,7-b]morphinan related to naltriben has been synthesised using a radical induced cyclisation of 6β-O-(2-bromophenyl)codeine, itself prepared by a Mitsunobu reaction between codeine and 2-bromophenol. A Stille coupling between codeine 6-O-trifluoromethanesulfonate and vinyltri(butyl)tin leads to a 6-deoxyvinyl-codeine derivative, which can be reacted with electron-poor dienophiles to afford 6,7-fused cycloadducts.

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