Synthesis of Substituted 1-Thiocyanatobutadienes and their Application in a Diets-Alder/[3,3] Sigmatropic Rearrangement Tandem Reaction

摘要

The retrosynthetic analysis of Ibogamine,a natural psychotropic alkaloid with exceptional anti-addictive properties found in both enantiomeric forms,requires an efficient access to a racemic cyclohexene.This cyclohexene can be obtained via the sequence Diels-Alder/[3,3] sig-matropic rearrangement reaction starting from substituted 1 -thiocyanatobutadienes.An efficient synthesis of the enone,a stable precursor of 1-thiocyanatobutadienes,is reported.Enolisation of this enone was studied to find the optimal conditions to get the desired 1-thiocyanatobutadienes with good Z-selectivity.