Approaches to the total synthesis of montanine-type alkaloids: a first synthesis of (±)-4a,11a-cis-11,11a-anti-5,11-methanomorphanthridine and its trans-isomer
Abstract
The title compounds (3) and (4) were synthesised by reductive cyclisation of cis- and trans-11-hydroxymethyl-N-tosylmorphanthridines (15) and (16) derived from cis- and trans-nitrocyclohexane derivatives (5) and (6) with sodium bis(2-methoxyethoxy)aluminium hydride in boiling toluene.