Synthesis and antiallergenic properties of 3-n-pentadecyl- and 3-n-heptadecylcatechol esters

A synthetic procedure is described for the preparation of 3-n-pentadecyl- and 3-n-heptadecylcatechols and their acetate and alaninate esters. The Wittig reagent prepared from 2,3-dimethoxybenzyltriphenylphosphonium bromide (III) was coupled with 1-tetradecanal or 1-hexadecanal to give the olefins IV and V, respectively. Catalytic reduction of IV and V followed by demethylation with boron tribromide afforded VIII and IX. The acetates were prepared using acetic anhydride and pyridine, while the alaninates were prepared using N-(tert-butoxycarbonyl)-L-alanine and dicyclohexylcarbodiimide followed by removal of the tert-butoxycarbonyl group with hydrogen chloride gas. The esters were active in guinea pigs in the production of tolerance and desensitization or hyposensitization to poison ivy-type contact dermatitis.