The 2-exo,7-exo,10-exo isomer of 11-oxa-tricycolo[6.2.1.0(2,7)]undec-4-ene-9,10-diyl diacetate

Abstract

The title compound, (2-exo, 7-exo, 9-exo, 10-exo)-11-oxatricyclo[ 6.2.1.0(2,7)] undec-4-ene-9,10-diyl diacetate, C14H18O5, was synthesized in the same way as its 9-endo, 10-endo isomer. The X-ray study showed that the Diels-Alder reaction of 5-exo, 6-exo-diacetato-7-oxabicylclo[2.2.1] hepta-2-ene with 3-sulfolene, a protected 1,3- butadiene, yields the 2-exo, 7-exo product, i. e. reacts in the same way as the 5-endo, 6-endo isomer of the starting compound. Intermolecular C-H center dot center dot center dot O interactions link the molecules into infinite chains extending along the b axis of the monoclinic crystal structure.