H. Greiving et al., SYNTHESIS, PHOTOPHYSICAL AND PHOTOCHEMICAL PROPERTIES OF 4 [2.2] CINNAMOPHANE ISOMERS HIGHLY EFFICIENT STEREOSPECIFIC [2+2] PHOTOCYCLOADDITION, Journal of the Chemical Society, Chemical Communications, (9), 1994, pp. 1075-1076
Anchoring two acryloyl substituents onto a paracyclophane:skeleton gen
erates four 'cinnamophane' isomers. one of which, the pseudo-gem, unde
rgoes a 'topochemical' reaction in solution.