Synthesis of Substituted 1‐Thiocyanatobutadienes and Their Application in a Diels—Alder/[3,3] Sigmatropic Rearrangement Tandem Reaction.

Abstract

Summary. 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] sigmatropic 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.