Amide acetal Claisen rearrangement in the synthesis of mesembrane alkaloids
Abstract
The synthesis of primary and secondary allylic alcohols (differing in the degree of steric hindrance) and of amide acetals (achiral and chiral) is reported. These compounds were used as substrates in the amide acetal Claisen rearrangement, and the effect of Lewis acids on the stereoselectivity of the reaction was studied. The rearrangement products have been applied to the synthesis of the mesembrane alkaloids (–)-mesembranone, rac-O-methyljoubertiamine and joubertiamine.