The role of β-bulky substituents in aldol reactions of boron enolates of methylketones with aldehydes: Experimental and theoretical studies by DFT analysis

Article abstract of DOI:10.1021/jo2023119

In this work, we show the influence of the volume of the β-substituents on the levels of 1,5-stereoselectivities of aldol reactions of boron enolates generated from β-alkoxy methylketones with aldehydes. Excellent levels of 1,5-syn stereoinduction were obtained when the β-protecting group is a silicon ether. This remarkable selectivity is attributed to the volume of the β-bulky substituent of the corresponding boron enolate. We have investigated a stereochemical model using DFT analysis to rationalize the sense of 1,5-syn stereoselectivities of β-alkyl-β- alkoxy methylketones.