Asymmetric synthesis of both enantiomers of point-difluorinated-eldanolide, analogues of insect sex pheromone.
Substitution of two fluorine atoms on organic molecules is expected to alter both chemical reactivity and biological activity due to the strong electron-withdrawing nature of fluorine. The synthesis of partly gem-difluorinated compounds remains a significant challenge to synthetic organic chemists. We report that [2,3]-Wittig rearrangement of 1,1,2-trifluoroallylic ether gave a new type of partly gem-difluorinated allylic alcohol: 6-methyl-4,4,5-trifluorohept-1,5-dien-3-ol, 3, in a highly stereoselective fashion, and optical resolution of alcohol 3 was accomplished via lipase PS(PCL)-catalyzed reaction. Using this alcohol as the starting material, the first asymmetric synthesis of both enantiomers of point-fluorinated-eldanolides, 2,2,5,5,6-pentafluoroeldanolide 1 and 5,5,6-trifluoroeldanolide 2, analogues of the sex pheromone of the male African sugarcane borer, has been demonstrated.
Itoh
T
T
Department of Chemistry, Faculty of Education, Okayama University, Japan. titoh@cc.okayama-u.ac.jp
Kudo
K
K
Tanaka
N
N
Zagatti
P
P
Renou
M
M
D000466:Alkadienes / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D005461:Fluorine / Q000737:chemistry*; D007313:Insecta; D012724:Sex Attractants / Q000138:chemical synthesis* / Q000737:chemistry
C431790:6-methyl-4,4,5-trifluorohept-1,5-dien-3-ol; D000466:Alkadienes; D012724:Sex Attractants; D005461:Fluorine