Novel oxazole derivatives of the formula
wherein R1 is hydrogen or a straight, branched or cyclic alkyl group of 1 to 6 carbon atoms, R2 is hydrogen, halogen, trifluoromethyl, or a straight, branched or cyclic alkylthio of 1 to 3 carbon atoms, and n is 1 or 2 or pharmaceutically acceptable salts or esters thereof are synthesized through several routes. The derivatives have hypoglycemic, glucose tolerance improving and insulin sensitivity increasing activities and are of value as antidiabetic drugs.
Electronically Mediated Selectivity in Ring Opening of 1-Azirines. The 3-X Mode: Convenient Route to 3-Oxazolines
作者:Marcus C. M. Sá、Albert Kascheres
DOI:10.1021/jo9518866
日期:1996.1.1
base-promoted reaction of methyl 2-phenyl-1-azirine-3-acetate (1) with aldehydes and acetone provides a new and simple route to the 3-oxazolines 5, which are formed in good yields by the electrophilic trapping of an imino anion produced by C-N bond cleavage in the 1-azirine enolate intermediate 6. Chloranil oxidation of 5 containing an aromatic substituent at C-2 affords oxazoles 7, while reaction of 5 containing