1,5-Asymmetric induction in the boron-mediated aldol reaction of beta-oxygenated methyl ketones

Quimica nova

Dias, Luiz C.¹  Aguilar, Andrea M.² 

[1] Universidade Estadual de Campinas, Campinas, Brasil;Universidade Federal de São Paulo, Diadema, Brasil

关键词: 1;    5-anti induction;    boronenolates;    aldol reactions.;   

DOI  :  10.1590/S0100-40422007000800036

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

High levels of substrate-based 1,5-stereoinductionare obtained in the boron-mediated aldol reactions of b-oxygenatedmethyl ketones with achiral and chiral aldehydes. Remote induction from theboron enolates gives the 1,5-anti adducts, with the enolate p-facialselectivity critically dependent upon the nature of the b-alkoxyprotecting group. This 1,5-anti aldol methodology has been strategicallyemployed in the total synthesis of several natural products. At present, theorigin of the high level of 1,5-anti induction obtained with the boronenolates is unclear, although a model based on a hydrogen bonding between thealkoxy oxygen and the formyl hydrogen has been recently proposed.

【 授权许可】

CC BY