A chirospecific synthesis of an ant venom alkaloid (5Z,8E)-3-heptyl-5-methylpyrrolizidine
作者:Hiroki Takahata、Hiroshi Bandoh、Takefumi Momose
DOI:10.1016/s0957-4166(00)82116-3
日期:1991.1
A straightforward and practical route for the chirospecific synthesis of both enantiomers of the ant venom alkaloid (5Z,8E)-3-heptyl-5-methylpyrrolizidine has been developed.
Enantioselective synthesis of an ant venom alkaloid (–)-[3S-(3β, 5β 8α)]-3-heptyl-5-methylpyrrolizidine
作者:Seiichi Takano、Shizuo Otaki、Kunio Ogasawara
DOI:10.1039/c39830001172
日期:——
An ant venom alkaloid (–)-[3S-(3β, 5β, 8α)]-3-heptyl-5-methylpyrrolizidine (1) has been synthesized in an enantioselective fashion from 3-(5-methyl-2-furly)propionaldehyde (2) employing enantioselective epoxidation at the key stage.
A short, chirospecific synthesis of the ant venom alkaloid (3R,5S,8S)-3,5-dialkylpyrrolizidines
作者:Hiroki Takahata、Hiroshi Bandoh、Takefumi Momose
DOI:10.1021/jo00042a017
日期:1992.7
The stereospecific synthesis of both (+)-xenovenine (1) and (+)-(3R,5S,8S)-3-methyl-5-(8-nonenyl)pyrrolizidine (2), found in ant venom, is described. The stereoselective intramolecular amidomercuration of the N-alkenylurethane 3, available from D-alanine, followed by oxidative demercuration provides the trans pyrrolidine alcohol 5. Thereafter, oxidation of 5 followed by Horner-Wadsworth-Emmons elongation of the ring appendage affords the relevant bicyclic precursors 7 and 9, which are stereoselectively converted into 1 and 10, respectively, by catalytic hydrogenation. The pyrrolizidine 10 is readily transformed into 2 by elaboration of the side chain at C5.