Sr. Angle et Jg. Breitenbucher, A GENERAL-ROUTE FOR THE SYNTHESIS OF ENANTIOPURE INDOLIZIDINE ALKALOIDS FROM ALPHA-AMINO-ACIDS - TOTAL SYNTHESIS OF (-MONOMORINE()), Tetrahedron letters, 34(25), 1993, pp. 3985-3988
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 c
onformationally restricted Claisen rearrangement of lactone 9 to pipec
olic ester 11.