Absolute configuration of thep-nitrobenzoate ester of the cycloadduct of (S)-4-hydroxy-2-pentynoate and acetic acid 8-acetoxy-1,4-dihydro-1,4-methanonapththalen-5-yl ester

The regio- and absolute stereochemistry of the title compound, ethyl 3,6-diacetoxy-11-[1-(4-nitrobenzoyloxy)ethyl]tetracyclo[6.4.1.0(2,7).0(9,12)]trideca-2,4,6,10-tetraene-10-carboxylate, C29H27O10, has been established. In the crystal structure, weak intermolecular hydrogen bonds link molecules into a three-dimensional network.