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Now showing items 31-36 of 36
An improved approach to B-norsteroids: An one-pot preparation of 3β-acetoxy-5-oxo-5,6-seco-cholestan-6-oic and 3β-acetoxy-5,17-dioxo-5,6-seco-androstan-6-oic acids
(Serbian Chemical Society, 1998)
A simple one-put procedure for the synthesis of the 5,6-seco-steroidal acids 9a,b in described in this paper. It consists of the epoxidation of the ▲ 5 -steroids, i.e., cholesteryl acetate (8a) and 17-oxo-aandrost-5-en-3β-yl ...
Semisynthesis of Taxol (R): an improved procedure far the isolation of 10-deacetylbaccatin III
(Serbian Chemical Soc, Belgrade, 1999)
From the needles of domestic yew, (Taxus baccata), 10-deacetylbaccatin III (10-DAB) call be isolated in quantities of up to 297 mg per kg of fresh needles. Additional quantities of 10-DAB call be obtained from the extract ...
Free radical ring expansion and subsequent reactions of intermediary carbon radicals
(Serbian Chemical Society, 1996)
Alkyl radicals, derived from ethyl 1-(bromoalkyl)-2-oxocyclo-alkanecarboxylates or from the corresponding thiohydroxamic esters, undergo a ring expansion reaction and subsequent intermoleculaar addition/elimination reactions. ...
Sesquiterpene lactones from plant species Centaurea solstitialis L.
(Serbian Chemical Society, 1998)
The identification of nine known guaianolides, i.e., solstitialin A, its 13-acetate, linichlorin B, cynaropicrin, centaurepensin (chlorohyssopifolin A), 17-epi-centaurepensin, 19-desoxychlorojanerin, 11ß,13-dihydrodesacy ...
Synthesis and oxidative transformations of 5-hydroxy-5α-cholest-8-en-3β-yl acetate
(Serbian Chemical Society, 1997)
5-Hydroxy-5α-cholest-8-en-3β-yl acetate (8) (prepared in 6 steps starting from 7-dehydrocholesteryl acetate (1) was transformed with ruthenium tetroxide to 5-hydroxy-8,9-dioxo-8,9-seco-5α-cholestan-3β-yl acetate (9). ...
Synthesis of modified 5,10:8,14-bisfragmentation cholestane derivatives
(Serbian Chemical Society, 1996)
In this paper is described a synthetic pathway to the modified 5, 10:8, 14-bisfragmentation cholestene derivatives 10, 11 and 12, which involves introduction of the Δ8(14)-double bond and 5α-hydroxyl group in the cholestane ...