Asymmetric synthesis of spiro 2-pyrrolidin-5-ones and 2-piperidin-6-ones
作者:Abood A. Bahajaj、Patrick D. Bailey、Madeleine H. Moore、Keith M. Morgan、John M. Vernon
DOI:10.1039/c39940002511
日期:——
Bicyclic lactams 14–17 are isomerised on treatment with aluminium trichloride in 1,2-dichloroethane to give spiro lactams in high yield and >3: 1 diastereoselectivity; from the structures of 19a and 22b determined by X-ray crystallography, it follows that the indenes 19 and 21 are formed preferentially with retention of configuration at the spiro carbon atom and the naphthalenes 20 and 22 with inversion.
Asymmetric synthesis of spiro 2-pyrrolidin-5-ones, 2-piperidin-6-ones and 1-isoindolin-3-ones. Part 1: N-Acyliminium ion cyclisations with an internal arene nucleophile
作者:Abood A Bahajaj、Madeleine H Moore、John M Vernon
DOI:10.1016/j.tet.2003.10.128
日期:2004.1
A series of chiral non-racemic 5,5- and 5,6-bicyclic lactams is prepared from (R)-phenylglycinol. These are isomerised on treatment with aluminium trichloride in 1,2-dichloroethane to give spiro lactams in high yield and >3:1 diastereoselectivity. From four structures determined by X-ray crystallography, it follows that spiro indenes are formed preferentially with retention of configuration at the spiro carbon atom and spiro naphthalenes with inversion. (C) 2003 Elsevier Ltd. All rights reserved.