Acyclic stereoselection—13: Aryl esters: reagents for threo-aldolization

CH Heathcock, MC Pirrung, SH Montgomery, J Lampe

Index: Heathcock, Clayton H.; Pirrung, Michael C.; Montgomery, Stephen H.; Lampe, John Tetrahedron, 1981 , vol. <23> 37, p. 4087 - 4095

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Citation Number: 144

Abstract

Preformed Li enolates of hindered aryl esters condense with aldehydes to give predominantly threo aldols. The method has been explored with esters 3 (DMP propionate), 4 (BHT propionate), and 5 (DBHA propionate). DMP propionate reacts with benzaldehyde and α-unbranched aliphatic aldehydes to give threo: erythro ratios of about 6.5: 1. However, with α-branched aliphatic aldehydes, ester 3 gives only threo-aldols. BHT propionate and ...