α-Amino Acids as Chiral Educts for Asymmetric Products. Chirospecific Syntheses of the 5-Butyl-2-heptylpyrrolidines from Glutamic Acid

Article abstract of DOI:10.1021/jo00208a016

Both enantiomers of trans-5-butyl-2-heptylpyrrolidine, an active and major component in the repellent venom of the ant Solenopsis fugax, have been synthesized with very high diastereomeric and optical purity from glutamic acid.Both enantiomers of the cis isomer also have been synthesized in an extension of our methodology to encompass the preparation of both cis and trans, optically pure, 2,5-disubstituted pyrrolidines and because of their potential entomological interest.Initially, a sulfide contraction process efficiently introduces the first side chain onto a pyroglutamate intermediate.Various strategies to elaborate the second side chain have been developed along with methods to control and establish the relative steroechemistry at C-2 and C-5 of the pyrrolidine ring with high selectivity. 2,5-Dialkyl-1-pyrrolidines, which also have been identified in the ant venom, can be prepared by these processes as well with specific absolute stereochemistry.