Improved Method for the Synthesis of β-Carbonyl Silyl-1,3-Dithianes by the Double Conjugate Addition of 1,3-Dithiol to Propargylic Carbonyl Compounds
作者:Sumit Mukherjee、Dimitra Kontokosta、Aditi Patil、Sivakumar Rallapalli、Daesung Lee
DOI:10.1021/jo901950e
日期:2009.12.4
Base-mediated double Conjugate addition of 1,3-propane dithiol to various silylated propargylic aldehydes and ketones allows for an efficient and scalable synthesis of beta-carbonyl silyl-1,3-dithianes.
Enantioselective reactions of α-methoxybenzyllithium generated by t-BuLi/chiral bis(oxazoline) complex with aldehydes
The title reaction is shown to afford the corresponding 1,2-diol monomethyl ethers in moderate-to-high levels of % ee (up to 98%) and % de (up to 90% anti), depending markedly on the aldehyde reactivity. The origin of the enantioselectivity is discussed in terms of a dynamic thermodynamic resolution mechanism. (C) 1999 Elsevier Science Ltd. All rights reserved.