Isolation of steroids containing a 5,7-diene functionality from a sterol mixture
CA 2118122 C · Owner: Yasuda, Dennis · Inventors: Tanabe, Masato; Johansson, John G.; Yasuda, Dennis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is provided for isolating 5,7-diene-containing steroids particularly , 3 .beta.-ols and esters of 3 .beta.-ols from a sterol, mixture. The method involves (1) treating the mixture with a dienophile or with an oxidizable dienophile precursor in combination with an oxidizing agent so as to provide a Diels-Alder adduct of the 5,7diene to be isolated, followed by (2) removal of the adduct from the mixture and (3) regeneration of the 5,7-diene with a suitable reducing agent. The invention also encompasses subsequent purification steps and intermediate modification of the Diels-Alder intermediate, e.g. wherein chemical conversion of the Diels-Alder adduct is effected prior to …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 14, 1993 and granted September 3, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 14, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 14, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.