Dehydrogenation of isolongifolene over 10% Pd C, in the vapour phase, at 450-±5° gave in∼ 23% yield a mixture of naphthalenes, consisting essentially of 1-methylnaphthalene (7· 5%). 1-methyl-7-isopropylnaphthalene (eudalene, 67· 5%), 1-methyl-6- isopropylnaphthalene (2· 8%) and 1, 6-dimethyl-7-ethylnaphthalene (7· 0%). The formation of these products is in complete accord with the structure I advanced earlier for ...