The structure and configuration of rishitinol (2), isolated fromtuber tissues of white potatoes (Solanum tuberlosum × S. demissum) infected by an incompatible race of Phytophtora infestans, were deduced from spectral and chemical data and confirmed by the synthesis of its recemate. 5,8-Dimethyl-1-tetralone-3-carboxylic acid (13) prepared from 2,5-dimethylbenzyl chloride was esterified, reduced, and