Catechuic acid and ethyl 2,4,5-trihydroxybenzoate from d-glucose

Abstract Synthesis of catechuic acid ( 1 ) and ethyl 2,4,5-trihydroxybenzoate ( 2 ) from d -glucose-derived β-ketoester is described. The polyhydroxylated β-ketoester obtained from the hydrolysis of sugar β-ketoester 3 was subjected to an aldol-type condensation to get 4 that on enolization, dehydration, and hydrogenation afforded ethyl 2,4,5-trihydroxybenzoate ( 2 ). On the other hand, hydrogenation of aldol product 4 afforded polyhydroxylated keto-carbasugar 6 , which on mild acid treatment and ester hydrolysis in basic media led to catechuic acid 1 . Intermediate 4 is co-related to 3-dehydroshikimic acid, a biochemical intermediate from d -glucose in the synthesis of pro-catechuic acid.