A new synthesis and stereocontrolled functionalization of substituted silacyclopent-3-enes.
C2-Substituted silacyclopent-3-enes have been prepared in good yields in two steps starting from commercially available diallylsilane 9. Coupling between carbanion of 9 and aldehydes or epoxides followed by ring-closing metathesis of the corresponding substituted diallylsilanes led to various silacyclopent-3-enes having a beta- or a gamma-hydroxysilane moiety. Dihydroxylation and epoxidation of the sila-cycle then led stereoselectively to polyhydroxylated silacyclopentanes. These processes were shown to occur with opposite topicity, offering a complementary and stereocontrolled access to diastereomeric polyols having up to five contiguous stereogenic centers.
Landais
Yannick
Y
Laboratoire de Chimie Organique et Organométallique, 351, Cours de la Libération, 33405 Talence Cedex, France. y.landais@lcoo.u-bordeaux1.fr
Mahieux
Cédrick
C
Schenk
Kurt
K
Surange
Sheetal S
SS