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Reactions of steroidal epoxides with strong organic bases and an investigation into the syntheses of some labelled pregnane derivatives

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dc.contributor.author Jahangir. en_US
dc.date.accessioned 2009-10-02T13:20:16Z
dc.date.available 2009-10-02T13:20:16Z
dc.date.issued 1982-10-02T13:20:16Z
dc.identifier.uri http://hdl.handle.net/10464/2761
dc.description.abstract Reactions of 5,6- and 4,5-epoxycholestane derivatives with strong bases were investigated. Epoxidation of 3a-acetoxycholest-5-ene also gave a new compound along with the anticipated epoxides. Interconversions of the latter were observed. Some possible mechanisms of its formation and rearrangements have been pIioposed. No reaction was observed with any of the 5,6- and 4,5-steroidal epoxides employed in the present study, using potassium tertiary butoxide under refluxing conditions. n-Butyllithium reacted only with 5,6-epoxycholestanes bearing a ketal moiety at the C3 carbon. Opening of the ketal group was observed with n-butyllithium in the case of a ~-epoxide. The reaction was also investigated in the absence of epoxide functionality. A possible mechanism for the opening of ketal group has been proposed. Lithium diethylamide (LDEA) was found effective in rearranging 5,6- and 4,5-epoxides to their ~orresponding allylic alcohols. These rearrangements presumably proceed via syn-eliminations, however the possibility of a corresponding anti-elimination has not been eliminated. A substituent effect of various functional groups (R = H, OH, OCH2CH20) at C3 has-been observed on product distribution in the LDEApromoted rearrangements of the corresponding epoxides. No reaction of these epoxides was observed with lithium diisopropylamide (LDA) • In the second part of the project, several attempts were made towards the sYRthesis of deoxycorticoste~one~17,2l,2l~d3' a compound desirable for the 2l-dehydroxylation studies of deoxycorticosterone. Several routes were investigated, and some deuterium labelled pregnane derivatives were prepared in this regard. Microbial 21-hydroxylation of progesteronel7,21,21,2l- d4 by ~ niger led to loss of deuterium from C21 of the product. An effort was made to hydroxylate progesterone microbially under neutral condtions. en_US
dc.language.iso eng en_US
dc.publisher Brock University en_US
dc.subject Epoxy compounds. en_US
dc.subject Steroids. en_US
dc.subject Organic bases. en_US
dc.subject Pregnane. en_US
dc.subject Organic compounds--Synthesis. en_US
dc.title Reactions of steroidal epoxides with strong organic bases and an investigation into the syntheses of some labelled pregnane derivatives en_US
dc.type Electronic Thesis or Dissertation en_US
dc.degree.name M.Sc. Chemistry en_US
dc.degree.level Masters en_US
dc.contributor.department Department of Chemistry en_US
dc.degree.discipline Faculty of Mathematics and Science en_US


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