Palladium-catalysed spirocyclisation of 3-acetoxy-1-(4-aminoalkyl)-cyclohexenes. Synthesis of (±)-depentylperhydrohistronicotoxin

Abstract

Palladium(0)-catalysed cyclisation of 3-acetoxy-1-(4-aminoalkyl)cyclohexenes provides easy access to the 1-azaspiro[5.5]undecane ring system found in the histrionicotoxins; this has been exploited in a synthesis of (±)-depentylperhydrohistrionicotoxin.