Diastereoselective synthesis of 3,4-disubstituted 5-(p-tolylsulfinyl)-5,6-dehydropiperidin-2-ones: chirality transfer in the enantioselective synthesis of ethyl (+)-(3S,4aS,7aS)-1-oxo-octahydro-1H-cyclopenta[c]pyridine-3-carboxylate
作者:Hassan Acherki、Carlos Alvarez-Ibarra、Juan F. Collados Luján、María L. Quiroga-Feijóo
DOI:10.1016/j.tetasy.2005.11.009
日期:2005.12
The base-mediated reaction of enantiomerically pure alpha-sulfinylketimine (+)-1 with (E)-alpha,beta-disubstituted propenoate esters afforded 3,4-disubstituted-5-(p-tolylsulfinyl)-5,6-dehydropiperidin-2-ones 9 alpha-13 alpha and 14 with high or complete diastereoselectivity. A sole diastereomer of the four possible ones, with regard to the nature of ester, was isolated, which revealed the stereocontrol of the chiral sulfinyl group in the Michael reaction and transenolization steps. In addition, the enantioselective synthesis of ethyl (+)(3S,4aS,7aS)-1-oxo-octahydro-H-1-cyclopenta[c]pyridine-3-carboxylates (+)-17 alpha is described (five steps; 47% yield; ee >= 97%). The absolute configuration of stereocentres introduced in (+)-17 alpha was assigned on the basis of H-1 NMR data. (c) 2005 Elsevier Ltd. All rights reserved.