Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1992-07-01
1993-08-31
Ivy, C. Warren
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D31300
Patent
active
052410838
ABSTRACT:
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 activated to a mesylate leaving group. The resultant 13-.alpha.-mesylate is then displaced with a cesium carboxylate and one equivalent of the respective carboxylic acid, ending with the ester group being converted to the 13-.beta.-hydroxy configuration by transesterification in high yield.
REFERENCES:
patent: 4199569 (1980-04-01), Chabala et al.
patent: 4310519 (1982-01-01), Albers-Schonberg et al.
patent: 4895837 (1990-01-01), Mrozik et al.
patent: 4906619 (1990-03-01), Eskola et al.
Cainelli et al., Tetrahedron, 41: 1385-1392 (1985).
Hughes et al., J. Am. Chem., 110: 6487-6491 (1988).
Mitsunobu, Synthesis, pp. 1-28 (1981).
Mrozik et al., J. Med. Chem., 32: 375-381 (1989).
Bill Timothy
Larsen Robert D.
Senanayake Chris H.
Singh Sheo B.
Vernhoeven Thomas R.
Ayler Sylvia A.
Daniel Mark R.
DiPrima Joseph F.
Ivy C. Warren
Merck & Co. , Inc.
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