2-[3-(2-Carboxycyclohexylmethyloxy)phenyl]propionic acid → 2-(6,6a,7,8,9,10,10a,11-Octahydro-11-oxodibenz[b,e]oxepin-3-yl)propionic acid

Participants

Reaction Conditions

Reaction Steps

2-[3-(2-Carboxycyclohexylmethyloxy)phenyl]propionic acid (14 g) was added to polyphophoric acid (80 g) and the mixture was heated with stirring for 2.5 hours in an oil bath maintained at 100° C. The reaction mixture was diluted with water and extracted with ethyl acetate. The ethyl acetate layers were washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. The residue was chromatographed on silica gel, using methanol-chloroform (2:98, v/v) as an eluent, to give 2-(6,6a,7,8,9,10,10a,11-octahydro-11-oxodibenz[b,e]oxepin-3-yl)propionic acid (1.05 g) as an oil. IR νmaxfilm cm-1 : 1700, 1680 (C=O). HRMS m/e: 288.1390 (M+) (Molecular weight calculated for C17H20O4 : 288.1362).

Provenance & Evidence