Abstract
The asymmetric Diels-Alder reactions between (3R)-4,4-dimethyl-2-oxopyrrolidin-3-yl acrylate derivatives and three N-Z-protected 1-aminodienes have been investigated both in solution and on a solid support. Comparable results for each reaction were observed with the formation of the corresponding constrained cyclic ß-amino acids in high yield and moderate-to-good selectivity when using optimized conditions. A detailed comparison of both solution and solid-support synthesis by conventional heating and microwave activation revealed that the microwave technique is often advantageous. We have also demonstrated that the reaction on a solid support offered an excellent resolution of the problem of low reactivity and instability of the reagents.