Microwave-induced synthesis of 2,3-unsaturated O-glycosides under solvent-free conditions
作者:Ronaldo N. de Oliveira、João R.de Freitas Filho、Rajendra M. Srivastava
DOI:10.1016/s0040-4039(02)00156-9
日期:2002.3
Microwave irradiation of it mixture of tri-O-acetyl-D-glucal 1 and an appropriate alcohol 2a f. in the presence of Montmorillonite K-10 as a catalyst, provided unsaturated glycosides 3a-f in much shorter time and in yields comparable with conventional heating. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis, separation and configuration determination of diastereoisomers of (R,S)-1-methyl-3-[3-(aryl)-1,2,4-oxadiazol-5-yl] propyl 2,3-dideoxy-α-d-erythro-hex-2-enopyranosides
作者:Rajendra M. Srivastava、João R. de Freitas Filho、Maria José da Silva、Suzana C. de Melo Souto、Gene B. Carpenter、W.M. Faustino
DOI:10.1016/j.tet.2004.08.075
日期:2004.11
yielding all diastereoisomers in the pure form. One of them 5d was subjected to a single crystal X-ray analysis to determine the correct configuration at the asymmetric carbon atom of the aglycone. The methyl signals of the diastereomers helped to assign the configuration of each diastereoisomer. Molecular orbital calculations of 5d using the semi-empirical method (AM1) has been performed to compare its