226 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS /•- Patchoule13e HN& --H 2 Patchoulipyr[dine Guaiol H Dihydro -- a --guaiene dihydroepig uaipyridine Figure 36 French workers who started from homocamphor. This was converted in a number of steps to a diketone which was then transferred into the pyridine. Some of the hydrocarbons found in guaiacwood oil have also been found in patchouli oil (104). The main constituents of guaiacwood oil are the two sesquiterpene alcohols guiaol and bulnesol. Treatment of these alcohols with a small quantity (0.01 ta) of sulphuric acid produces a number of the hydrocarbons found in patchouli oil. These are obtained as a mixture and isolation of the desired hydrocarbons is difficult (see Fig. 37). A total synthesis (105) of guaiol has been reported but as guaiacwood oil is one of the cheaper sesquiterpene containing essential oils, this work appears to be of academic interest only. Treatment of guaiol with sulphuric acid, para-toluenesulphonic acid or iodine yields a cyclic ether guaioxide (Fig. 38). This ether has been claimed

SESQUITERPENES IN THE PERFUMERY 1NDUSTRY 227 ,01 •04 AcOH Guaiol O, 01, M H2•S 04 AcOH Bul nesol Figure 37. Hydrocarbons l•rom guaiol and bulnesol. (104).