Abstract
A double-head hapten containing a pyrocatechol and .alpha.-methylene-.gamma.-buryrolactone moiety and monofunctional haptens with either one of these moieties connected by a 6-C chain were synthesized, and their sensitizing capacity was tested on guinea pigs. In the double-head hapten, only the pyrocatechol end is recognized. A possible interpretation of the biological results is offered.