Regiocontrolled Synthesis of Carbocycle-Fused Indoles via Arylation of Silyl Enol Ethers with <i>o</i>-Nitrophenylphenyliodonium Fluoride
作者:Tetsuo Iwama、Vladimir B. Birman、Sergey A. Kozmin、Viresh H. Rawal
DOI:10.1021/ol990759j
日期:1999.8.1
[formula: see text] A new, regiocontrolledsynthesis of carbocycle-fused indoles has been developed. The two-step procedure involves first the regiospecific arylation of silyl enol ethers with o-nitrophenylphenyliodonium fluoride (1). Reduction of the nitro group on the aromatic ring with TiCl3 followed by spontaneous condensation of the aniline with the ketone then affords the indole products.
Regio- and Stereospecific Synthesis of Cholesterol Derivatives and Their Hormonal Activity inCaenorhabditis elegans
作者:Arndt W. Schmidt、Thomas Doert、Sigrid Goutal、Margit Gruner、Fanny Mende、Teymuras V. Kurzchalia、Hans-Joachim Knölker
DOI:10.1002/ejoc.200600394
日期:2006.8
identified. Herein, we describe the regio- and stereospecificsynthesis of a number of cholesterol derivatives. The lithium–ammonia reduction of 4-cholesten-3-one was utilized to develop a general method for the introduction of diverse functional groups at C-4α of 5α-cholestan-3β-ol. Stereoselective functionalization at C-7 was achieved starting from 7-ketocholesterol derivatives. 6-Keto-5α-cholestan-3β-ol
Regioselective enolization of optically active 3-keto steroids using chiral lithium amides
作者:Masao Sobukawa、Makoto Nakajima、Kenji Koga
DOI:10.1016/s0957-4166(00)86317-x
日期:1990.1
4α-Bromo-5α-cholestan-3β-ol and nor-5α-cholestan-3β-ol derivatives—stereoselective synthesis and hormonal activity in Caenorhabditis elegans
作者:René Martin、Ratni Saini、Ingmar Bauer、Margit Gruner、Olga Kataeva、Vyacheslav Zagoriy、Eugeni V. Entchev、Teymuras V. Kurzchalia、Hans-Joachim Knölker
DOI:10.1039/b904001c
日期:——
describe the stereoselective synthesis of 4α-bromo-5α-cholestan-3β-ol, 21-nor-5α-cholestan-3β-ol, 27-nor-5α-cholestan-3β-ol and 21,27-bisnor-5α-cholestan-3β-ol. In order to clarify the in vivometabolism of cholesterol, these compounds have been used for feeding experiments in Caenorhabditis elegans. Our preliminary results provide important insights into the metabolism of cholesterol in worms.