Stereocontrolled synthesis of the CDF part of Aconitum alkaloids via intramolecular double Michael reaction

Abstract

Intramolecular double Michael reaction of the α,β-unsaturated enone ester (5) using lithium hexamethyldisilazide produced the tricyclo[5.2.2.0^1,5] undecane derivative (4) in a highly stereoselective manner. The annulation of (5) was further investigated under various conditions. The tricyclic compound (4) was converted into the tetracyclo[7.3.1.0^4,12.0^5,13]tridecane derivative (31), the CDF part of Aconitum alkaloids, via a Wagner–Meerwein-type rearrangement.