Total synthesis of (±)-limaspermine and formal synthesis of (±)-aspidospermine using organoiron complexes

Abstract

The total synthesis of the C-18 oxygenated aspidosperma alkaloid (±)-limaspermine (3) is described using tricarbonyl{-1–4-η-[1-methoxy1-4-(3-methoxycarbonylpropyl)cyclohexa-1,3-diene}iron (15) as a readily available ring C precursor. A formal synthesis of (±)-aspidospermine (1) from 4-ethylanisole, via the organoiron derivative (23) is also described as a model study for an alternative route to the C-18 functionalised alkaloids.