抄録
The silyl group acts as a directing group and a good leaving group in organic synthesis. We have been focusing on developing stereoselective synthesis utilizing these feature of silyl groups. In this context, stereoselective construction of multiple stereogenic centers using simple acylsilanes and transformation of cyclopropyl silyl ketones are described. The aldol-Tishchenko reaction of acylsilanes gives the corresponding 1,3-diol derivatives having three contiguous stereogenic centers with perfect levels of stereochemical control in one-pot. On the other hand, Mukaiyama aldol reaction of acylsilane silyl enol ethers derived from acylsilanes with dimethyl acetals affords the corresponding β-methoxyacylsilanes in high d.e.. The following 1,3-asymmetric induction in the nucleophilic addition furnished three diastereoisomers of 1,3-diol derivatives having the three contiguous stereogenic centers among four possible diastereomeric products with high stereoselectivity. Meanwhile, treatment of cyclopropylsilylmethanols derived from cyclopropyl silyl ketones with acid-catalyst gives the corresponding silyl-substituted homoallyl derivatives in high yields with good stereoselectivity. The protodesilylation of the resulting products proceeds with complete retention of the configuration.
