Asymmetric [2,3]-Wittig rearrangement induced by a chiral carbanion whose chirality was transferred from an epoxide.
[reaction: see text] The enantioselective [2,3]-Wittig rearrangement of 1-allyloxy-1-(naphthalen-2-yl)-4-siloxy-2,4-pentadienyl anion, derived from optically enriched 4,5-epoxy-1-(naphthalen-2-yl)-5-silyl-2-pentenyl allyl ether via a base-induced ring opening of the epoxide followed by Brook rearrangement, has been studied. The chirality of the epoxide was transferred to the alcohols in up to 97% ee, depending on the solvent used. The best result was obtained in 1,4-dioxane at a temperature above room temperature.
Sasaki
Michiko
M
Department of Synthetic Organic Chemistry, Graduate School of Medical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8551, Japan.
Higashi
Mariko
M
Masu
Hyuma
H
Yamaguchi
Kentaro
K
Takeda
Kei
K