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
described. The first step involves a Stobbe condensation of benzaldehydes 9–11 with dimethyl succinate. Subsequent transposition of the ester and reduction of the double bond provides the building blocks 15–17 for an intramolecular Friedel–Crafts acylation. ABC-lactones 22–25 are prepared from γ-keto esters 18–21 by saponification, subsequent reduction with sodium borohydride followed by acid-catalyzed