Synthesis of and allergic contact dermatitis to bicyclo-[2,2,1]-heptyl-alpha-methylene-gamma-butyrolactones derived from norbornene and camphene.

Three new lactones, 2-oxo-3-methylene-4,7-methanobenzofuran and two alpha-methylene spirolactones, 3',3'-dimethylspiro(2-oxo-3-methylenefuran-5,2'-norbornane), were synthesized and their skin activity was tested on one human volunteer and on guinea pigs. The man, sensitized to Frullania, was found sensitive to the above lactones and also reacted to frullanolide and alantolactone. The guinea pigs, experimentally sensitized to alantolactone, cross-reacted to 2-oxo-3-methylene-4,7-methanobenzofuran and the two alpha-methylene spirolactones, and also to isolantolactone and frullanolide.