An efficient synthesis of the side-chain precursor crucial to the preparation of 18-methoxycoronaridine (18-MC) has been developed. This procedure represents an improvement upon the original synthesis, in which regioisomers were separated by chromatography to provide the requisite precursor. Incorporation of the protected primary alcohol moiety in the early stages of the synthesis provides the requisite regioisomer unambiguously and obviates the need for chromatography at any point.
18-methoxycoronaridine - 18-MC - debenzylation