Procedure for the inversion of the sterochemistry at c13 of avermectin aglycone compounds
CA 2068388 A1 · Owner: Jones, Todd K. · Inventors: Jones, Todd K.; Mrozik, Helmut
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The natural stereochemistry at the, 13-position of avermectin aglycones normally, .alpha.-oriented or below the plane of the molecule is, inverted or epimerized into the .beta.-position. The procedure starts with the avermectin aglycone compounds where the 13.alpha.-hydroxy group is substituted with a leaving group. Treatment of the substituted compound with tetra alkyl ammonium nitrate displaces the leaving group, substitutes a nitrate ester or a nitrooxy group, for the hydroxy and inverts the 13-stereochemistry to .beta.. Reduction of the nitrooxy group returns the 13-hydroxy group and retains the 13-.beta. configuration. The intermediate 13-nitrooxy compounds are themselves potent …
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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.
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- Filed May 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 11, 2014.
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