Facile transformation of 1-methoxynaphthalenes to octahydrophenanthrenes application to the total synthesis of (±)-sempervirol methyl ether, (±)-sugiol methyl ether, (±)-nimbiol methyl ether, and (±)-nimbidiol dimethyl ether
general method has been developed for the synthesis of the tricyclic aromatic ketones 4,12,13 and 14 from the 1-methoxynaphthalenes 8,9,10 and 11 respectively. The transformations of the ketones 4,12,13 and 14 into the diterpene ethers (±)-sempervirol methylether (7), (±)-sugiol methylether (15), (±)-nimbiol methylether (16), and (±)-nimbidiol dimethyl ether (17) have been successfully accomplished
Influence of electron donating aromatic substituents on the ruthenium tetroxide-catalysed oxidation of (±)-podocarpa-8,11,13-trienes
作者:Sukumar Ghosh、Usha Ranjan Ghatak
DOI:10.1016/s0040-4020(01)88267-3
日期:1992.1
and the diketone 9. Similar oxidation reaction of the hexahydrophenanthrene 7a led to the α, β-unsaturated tricyclic ketone 11a and the tetrahydronaphthalene dicarboxylic anhydride 12. In contrast, 7b produced the diketone 10b and the α,β-unsaturatedketone 11b as the sole isolated products.
Isolation, synthesis, and anti-tumor activities of a novel class of podocarpic diterpenes
作者:Yi Xiong、Kuiwu Wang、Yuanjiang Pan、Hongxiang Sun、Jue Tu
DOI:10.1016/j.bmcl.2005.11.023
日期:2006.2
A novel unusual 17-carbon diterpenoid, named (+)-7-deoxynimbidiol, was isolated from the stalks of Celastrus hypoleucus (Oliv.) Warb. Its racemate and derivatives were synthesized, and the inhibitory activities of these compounds against four cultured human-tumor cell lines were evaluated. The structure-activity relationship was discussed. (c) 2005 Elsevier Ltd. All rights reserved.
Ghosh, Sukumar; Banik, Bimal K.; Ghatak, Usha Ranjan, Journal of the Chemical Society. Perkin transactions I, 1991, # 12, p. 3189 - 3194
Formation of episulfonium ions from alkenes. Application to the synthesis of higher order carbocycles via episulfonium ion initiated polyene cyclizations