Non-polymeric Uses of Urushiol

To aid chemical uses, the separation of urushiol on cation exchange resins has been employed (ref. 320). Recent work has concentrated on the preparation of various salts from Al, Sb (ref.321), Ti (IV), Fe(ll) and Cu(ll) (ref. 322). Aluminium compounds possessed good thermal stability, antimony compounds flame-retardant properties and titanium componds excellent anticorrosion action. 2 1 Complexes 

The hydroxylation of benzene with hydrogen peroxide in the presence of urushiol and Fe(lll), both probably in compiexed form, afforded a 45% yield of phenol (ref. 323). 

Not only a wide range of cations complex with the catechol system of urushiol but the borate anion also undergoes quite strong association. Thus urushiol together with Aliquat 336 was valuable for the solvent extraction of this anion probably through the formation of 1 1 and 2 1 chelates (ref.293). 

The cleavage of urushiol by catechol-2,3-dioxygenase has been studied (ref. 324) and the oxidation of anacardic aldehyde to urushiol with manganeses dioxide (ref. 325), an alternative to the Dakin reaction descibed some years ago (ref. 88). Experiments on the methylation of urushiol (refs. 88,89) Indicate that the 3-hydroxyl group reacts preferentially under mild conditions. Hydrogenated urushiol, 1,2-dihydroxy-3-pentadecylbenzene, reacted similarly to form 1-methoxy-2-hydroxy-3- 

The oxidation of 3-pentadecylcatechol in various solvents has been studied under aerobic conditions (ref. 327). The enzymic, thermal and oxidative reactions leading to the polymerisation of urushiol have been examined (ref. 328). Many other papers presented at the 1993 symposium on oriental lacs have been concerned with the same problem. 

---