Steroids. Part XXXV. Preparation of the epimeric 2-hydroxy-19-nor-5α-cholestanes
作者:C. W. Shoppee、J. C. Coll、Ruth E. Lack
DOI:10.1039/j39700001893
日期:——
2β,19-Epoxy-5α-cholestane, readily obtained from 5α-cholestan-2β-ol by treatment with lead tetra-acetate, on acetolysis with acetic anhydride catalysed by pyridinium hydrochloride or by boron trifluoride gave a variety of products, from which were derived 5α-cholestan-19-oic acids, 5α-cholest-1- and -2-en-19-aldehydes, and 5α-cholestan-19-ols. 2α-Acetoxy- and 2α-methoxy-5α-cholestan-19-oic acids resisted
Structural requirements for the thallium(<scp>III</scp>)-mediated cyclisation of unsaturated alcohols. A novel fragmentation reaction producing 19-norsteroids
作者:Pavel KočOvský、Vratislav Langer、Adolf Gogoll
DOI:10.1039/c39900001026
日期:——
The unsaturatedalcohol (1) is readily cyclised to the hydroxytetrahydrofuran (3) by means of thallium(III), whereas its congener (4) has been found to give (7) as the product of a novel, stereoelectronically controlled, fragmentation; the scope of the tandem electrophilic cyclisation/solvolysis is discussed; the structure of (7) has been determined by X-ray crystallography.
Kocovsky, Pavel; Stieborova, Irena, Journal of the Chemical Society. Perkin transactions I, 1987, p. 1969 - 1974
作者:Kocovsky, Pavel、Stieborova, Irena
DOI:——
日期:——
Kocovsky, Pavel, Collection of Czechoslovak Chemical Communications, 1983, vol. 48, # 12, p. 3660 - 3673
作者:Kocovsky, Pavel
DOI:——
日期:——
Stereo- and regiocontrol of electrophilic additions to cyclohexene systems by neighboring groups. Competition of electronic and stereoelectronic effects and comparison of the reactivity of selected electrophiles