‘Syn-effect’ in the diastereoselective alkylation of 3-[(E)-α,β-unsaturated-γ-substituted]-N-acyloxazolidinones
作者:Jacqueline Jiménez、JuánCarlos Ramírez、Gabriela Huelgas、Ruth Meléndrez、Blanca M. Cabrera-Vivas、Estibaliz Sansinenea、Aurelio Ortiz
DOI:10.1016/j.tet.2015.05.037
日期:2015.7
Synthetic methods for the formation of alkenes usually produce the E-alkene because it is more stable. However, in isomerization reaction (double bond migration) that takes place in alpha, beta-unsaturated carbonyl compounds, when these carbonyl compounds are exposed to strong bases, furnish Z-alkenes highly stereoselective depending on the gamma-substituent in the alpha, beta-unsaturated carbonyl. This stereo-selectivity can be attributed to the known Syn-effect. The synthetic value of this methodology is the achievement of chiral alcohol bearing an electron rich Z-alkene, as well as substituted, which was accomplished via removal of the oxazolidinone moiety under treatment with NaBH4, THF-H2O. (C) 2015 Elsevier Ltd. All rights reserved.