Hydrolysis of 1-substituted 7-oxanorborna-2,5-diene-2,3-dicarboxylates occurred regioselectively at the ester group in the 3-position to give monocarboxylic acids from which diesters containing two different alkoxy groups and amido esters were selectively prepared. Hydrogenation of these oxanorbornadiene derivatives followed by a retro-Diels–Alder reaction gave the corresponding furans as single regioisomers.
Key words
Diels–Alder reactions - hydrolyses - esters - amides - regioselectivity - furans - heterocycles