A general route for the synthesis of enantiopure indolizidine alkaloids from α-amino acids. Total synthesis of (+)-Monomorine

Article abstract of DOI:10.1016/S0040-4039(00)60596-8

The ant trail pheromone (+)-Monomorine was synthesized in 9 steps from N-t-BOC-L-alanine ethyl ester. The key step of the synthesis is the conformationally restricted Claisen rearrangement of lactone 9 to pipecolic ester 11.