Steroid cyclicsulfites. III. Conformational and configurational aspects of steroid 3,5-cyclicsulfites.
The reaction of 3beta, 5beta-dihydroxy cholestanes with thionyl chloride is shown to yield cyclicsulfite esters containing boat heterocyclic rings with the S=O oxygen axial or equatorial, depending upon the mode of formation. Treatment of a diol in pyridine at low temperature favors an equatorial S=O conformation while higher reaction temperatures in chloroform solution yield a mixture of axial and equatorial epimers. In the case of a 7alpha-bromo-6-oxo 3,5-sulfite, it has been shown that the S=O equatorial isomer may be converted to the axial isomer upon treatment with acid.
D000535:Aluminum; D002776:Cholestanes / Q000138:chemical synthesis*; D003499:Cyclic S-Oxides / Q000138:chemical synthesis; D004147:Dioxins / Q000138:chemical synthesis; D008094:Lithium; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D013260:Steroids, Heterocyclic / Q000138:chemical synthesis*
D002776:Cholestanes; D003499:Cyclic S-Oxides; D004147:Dioxins; D013260:Steroids, Heterocyclic; D008094:Lithium; D000535:Aluminum