Highly efficient epoxidation of unsaturated steroids using magnesium bis(monoperoxyphthalate) hexahydrate
作者:João F.S. Carvalho、M. Manuel Cruz Silva、M. Luisa Sá e Melo
DOI:10.1016/j.tet.2009.01.100
日期:2009.4
Fast generation of epoxides from the corresponding homoallylic and allylic steroidal olefins was developed by using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) as oxidant suspended in acetonitrile (CH3CN) at reflux temperature. The protocol involves the use of a safe readily available oxidant along with an easy work-up, which renders the process very efficient. Selective 4,5- and 5,6-epoxidations
Benzoyl trifluoromethanesulfonate. A mild reagent for the benzoylation of sterically hindered hydroxyls
作者:Lindsey Brown、Masato Koreeda
DOI:10.1021/jo00195a001
日期:1984.10
Efficient Chemoenzymatic Synthesis, Cytotoxic Evaluation, and SAR of Epoxysterols
作者:João F. S. Carvalho、M. Manuel Cruz Silva、João N. Moreira、Sérgio Simões、M. Luisa Sá e Melo
DOI:10.1021/jm9003973
日期:2009.7.9
A library of diastereomerically pure epoxysterols, prepared by combining chemical and enzymatic methodologies, was evaluated for cytotoxicity toward human cancer and noncancer cell lines. Unsaturated steroids were oxidized by magnesium bis(monoperoxyphthal ate) hexahydrate in acetonitrile, and the resulting epimeric epoxides were enzymatically separated using Novozym 435 or lipase AY. Some of the synthesized epoxysterols have potent cytotoxicity and higher activity on cancer cell lines HT29 and LAMA-84.
▵<sup>5</sup>-Cholestene-3β,4β,7α-triol and the Inhibition of the Oxidation of Hydroxyl Groups by Vicinal Substituents
作者:Seymour Lieberman、David K. Fukushima
DOI:10.1021/ja01167a119
日期:1950.11
Stereo- and regioselectivities in the epoxidation of some allylic alcohols by the dioxirane intermediate generated in the reaction of potassium caroate with acetone