Substitution of two fluorine atoms on organic molecules is expected to alte
r both chemical reactivity and biological activity due to the strong electr
on-with drawing nature of fluorine. The synthesis of partly gem-difluorinat
ed 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 o
ptical resolution of alcohol 3 was accomplished via lipase PS(PCL)-catalyze
d reaction. Using this alcohol as the starting material, the first asymmetr
ic 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.