Epoxide Formation by Indirect Electroreductive Coupling between Aldehydes or Ketones and Activated<i>gem</i>-Dichloro Compounds
作者:J. P. Paugam、S. Oudeyer、E. Léonel、J.-Y. Nédélec
DOI:10.1055/s-2004-815915
日期:——
Epoxides are prepared by indirect electroreductive coupling of carbonyl compounds (aldehydes or ketones) and activated gem-dichloro compounds. This process is more efficient with aryl ketones than with aryl aldehydes. Though yields are only moderate, this method offers the valuable advantage of avoiding the use of strong bases or peroxides.
Arynes are utilized in the syntheses of 1,2‐dihydroquinolines, epoxides, and phenolic ethers involving Diels‐Alder, Johnson‐Corey‐Chaykovsky, and Claisen‐type rearrangement reactions, respectively, through three different domino processes
Pure trans-(R,R)-diaryl-epoxides are obtained in two steps and under aprotic conditions using Eliel's oxathiane as the chiral auxiliary. The enantiomeric excesses, determined by chiral HPLC, are 97.9% to 99.9% and the oxathiane is recovered in 78% to 92% yield and may thus be re-used. Copyright (C) 1996 Elsevier Science Ltd