Synthesis of β-lactams and β-aminoesters via high intensity ultrasound-promoted Reformatsky reactions
作者:Nathan A. Ross、Robert R. MacGregor、Richard A. Bartsch
DOI:10.1016/j.tet.2004.01.002
日期:2004.2
Reformatskyreactions of an imine, an α-bromoester, zinc dust and a catalytic amount of iodine in dioxane under high intensity ultrasound (HIU) irradiation from an ultrasonic probe are explored. A series of 16 aldimines with varying electronic demands is evaluated as potential electrophiles for reactions with three α-bromoesters of differing steric demands. This HIU method is successful for both enolizable
The base induced ring opening of beta-lactam derivatives, 3, 5, 7, 9, 11 with LDA gave gamma-lactam derivatives, 4, 6, 8, 10, 12 stereo selectively. The gamma-lactam derivatives were formed stereoselectively depending on C-3 substituent of P-lactam derivatives. (C) 2005 Published by Elsevier Ltd.