The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 28, 1977
Filed:
Apr. 28, 1975
William S Johnson, Portola Valley, CA (US);
The Board of Trustees of Leland Stanford Junior University, Stanford, CA (US);
Abstract
Precursor compounds are provided for use in the synthesis of 11-chalcogensubstituted steroids and nor-steroids, particularly 18-, 19- and A-nor-steroids. The compounds are acyclic or substituted polyenine with the olefinic groups having the proper geometry to provide the natural ring fusions upon cyclization. To initiate cyclization, a chalcogen atom is positioned in relation to a double bond, so that on protonation of the chalcogen atom, the resulting carbocation will interact with the double bond to form a pi bond if the cyclization initiator is carbocyclic and a sigma bond if the cyclization initiator is acyclic. Upon cyclization, it is found that the substituent at C-11 of the resulting steroid is in the alpha position. Various methods are provided for producing the cyclization precursor.