Synthesis of acetyl scopine. Intramolecular reactions of N-carbethoxy nortropine-3 alpha-benzenesulfenate

Abstract

The synthesis of acetyl scopine using tropine as a starting compound was achieved. Free radical phenylthio group transfer to the 6-position, in the reaction of N-carbethoxy nortropine-3 alpha-benzenesulfenate with hexabutylditin, is a key step of this synthetic approach to scopine. The reaction of N-carbethoxy nortropine-benzenesulfenate with tributyltin hydride in the presence of a radicophilic olefin involves Michael type alkylation at the 6-position of tropine skeleton affording 6-(2-carbethoxyethyl)-N-carbethoxy nortropine in 31% yield.