Tetrahedron

Asymmetric syntheses of (+)-negamycin,(+)-3-epi-negamycin and sperabillin C via lithium amide conjugate addition

SG Davies, O Ichihara, PM Roberts, JE Thomson

Index: Davies, Stephen G.; Ichihara, Osamu; Roberts, Paul M.; Thomson, James E. Tetrahedron, 2011 , vol. 67, # 1 p. 216 - 227

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Citation Number: 26

Abstract

The chemo-and enantioselective reduction of ethyl 4-chloroacetoacetate and the diastereoselective conjugate addition of enantiopure lithium N-benzyl-N-(α-methylbenzyl) amide to an α, β-unsaturated ester have been used as the key steps in the total asymmetric syntheses of (+)-negamycin (in 13 steps and 24% overall yield),(+)-3-epi-negamycin (in 13 steps and 10% overall yield) and sperabillin C (in 17 steps and 13% overall yield) from ...