Synthetic studies on vincorine: access to the 3a,8a-dialkyl-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole skeleton

Synthetic studies on vincorine are described; the conversion of 3-aminoethyl-3-alkyloxindoles to 3a,8a-dialkyl-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indoles has been achieved through an addition-cyclization sequence, and a fully functionalized key intermediate was constructed with this method.