Easy Access to cis-3-(Benzoxazol-2-yl)cyclopentanecarboxylic Acids from Camphorquinone and o-Aminophenols via an Unexpected Opening of Camphor Ring

An unexpected formation of cis-1,2,2-trimethyl-3-(benzoxazol-2-yl)cyclopenta-necarboxylic acids was observed as the result of an oxidative C-C bond cleavage of the camphor ring in the intermediate imine during the condensation reactions between camphoroquinone and o-aminophenols conducted under open air conditions.

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