Remote asymmetric induction with vinylketene silyl n,o-acetal.
A highly regio- and diastereoselective TiCl4-mediated vinylogous Mukaiyama aldol reaction using the chiral vinylketene silyl N,O-acetal has been developed. The present vinylogous Mukaiyama aldol reaction provides a unique and effective means of controlling remote asymmetric induction. The methyl group at the alpha-position is important in achieving a high level of stereoselectivity. From a synthetic point of view, this methodology can provide a one-step construction of delta-hydroxy-alpha,gamma-dimethyl-alpha,beta-unsaturated carbonyl unit that is seen in many natural polyketide products.
Shirokawa
Shin-Ichi
S
Faculty of Pharmaceutical Sciences, Tokyo University of Science (RIKADAI), 2641 Yamazaki, Nodashi, Chiba 278-8510, Japan.
Kamiyama
Masato
M
Nakamura
Tomoaki
T
Okada
Masakazu
M
Nakazaki
Atsuo
A
Hosokawa
Seijiro
S
Kobayashi
Susumu
S