Structure of the minor ozonolysis product of 19β,28-epoxy-A-neo-18α-olean-3(5)-ene
作者:N. I. Medvedeva、O. B. Flekhter、A. Gzella、L. Zaprutko
DOI:10.1007/s10600-006-0233-0
日期:2006.9
Synthesis of triterpenoid-based 1,2,4-trioxolanes and 1,2,4-dioxazolidines by ozonolysis of allobetulin derivatives
作者:Oxana B. Kazakova、Dmitri V. Kazakov、Emil Yu. Yamansarov、Natal’ya I. Medvedeva、Genrikh A. Tolstikov、Kyrill Yu. Suponitsky、Dmitri E. Arkhipov
DOI:10.1016/j.tetlet.2010.12.047
日期:2011.3
Oxidation of allobetulin derivatives with ozone results in good isolated yields of 1,2,4-trioxolanes and stable 1,2,4-dioxazolidines. Individual 3R,5R and 3S,5S diastereoisomers of allobetulin secondary ozonides were isolated and their structures confirmed by X-ray crystallographic analysis. Remarkable diastereoselectivity with formation of only the (3S,5S)-configured peroxides was observed during the oxidation of 1,5-di-O-methoxyoximinoallobetulin to dioxazolidines. (C) 2010 Elsevier Ltd. All rights reserved.
Synthesis of 4,5-Seco-Derivatives of Allobetulin
作者:N. I. Medvedeva、O. B. Flekhter、L. A. Baltina、F. Z. Galin、G. A. Tolstikov
DOI:10.1023/b:conc.0000039133.48494.db
日期:2004.5
4,5-Seco-betap,28-epoxy-18alpha-olean-3,5-dione was prepared by ozonation of 19beta,28-epoxy-18alpha-olean-3(5)-ene. The structures of the synthesized compounds were confirmed using spectral data.