Intramolecular Diels−Alder Cycloaddition ofN-Allyl-N-(2-furylmethyl)amides − First Step of a New Route Towards the Synthesis of a Densely Functionalized Pyrrolizidine Ring

Abstract

The intramolecular Diels−Alder reaction of N-allyl-N-(2-furylmethyl)amides to exo-N-acyl-3-aza-10-oxatricyclo[5.2.1.01,5]dec-8-enes is described. The cycloaddition is controlled not only by the size of the amide appendage, but also by electronegativity of the amide. An example of a new approach towards the synthesis of a highly functionalized pyrrolizidine ring, which links this Diels−Alder cycloaddition to an halogen atom transfer radical cyclization, is reported.