Stereocontrolled construction of seven-membered carbocycles using a combination of Brook rearrangement-mediated [3 + 4] annulation and epoxysilane rearrangement.
Reactions of delta-silyl-gamma,delta-epoxy-alpha,beta-unsaturated acylsilane with alkenyl methyl ketone enolate afford highly functionalized cycloheptenone derivatives via a tandem sequence featuring the combination of Brook rearrangement-mediated [3 + 4] annulation and epoxysilane rearrangement. The reactions using an opposite combination of three and four carbon units, in which an epoxysilane moiety was incorporated in the four-carbon unit, also give satisfactory results. Also, the possibility of chirality transfer from epoxide to remote positions via the tandem sequence using an optically active epoxide has been demonstrated.
Nakai
Yoshio
Y
Department of Synthetic Organic Chemistry, Graduate School of Medical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8551, Japan.
Kawahata
Masatoshi
M
Yamaguchi
Kentaro
K
Takeda
Kei
K