Configurational Relationships of Phenylated Carbinols. Iii

All the carbinols which have been directly correlated to lactic acid have been strictly aliphatic. A number of carbinols with phenyl groups has been studied but none correlated. Hewitt and Kenyonl pointed out that the phenylated carbinols possess much higher activities than the corresponding aliphatic ones of the same number of carbon atoms, and that the enhancement apparently increases as the phenyl group approaches the asym- metric carbon atom. But they made no direct correlations and must have assumed that the phenyl group does not cause an inversion of the sign of rotation. This paper deals with the correlation of a number of carbinols containing a phenyl group at different distances from the asym- metric carbon atom. The first studied was ethyl-P-phenethyl carbinol II which was correlated to lactic acid in the manner shown in the accompanying diagram. The results of these correlations show that levo-ethyl-p- phenethyl carbinol II and levo-ethyl-@-cyclohexethyl carbinol III are related to levo-ethylpropyl carbinol, that a phenyl group in the /3 position to the asymmetric carbon atom causes no inver- sion of the sign of rotation, but rather an enhancement, and that a cyclohexyl group likewise in the /3 position is roughly equivalent to a normal hexyl group. Further, the presence of a double bond in the OZ, fl position as in I causes an inversion of sign just as in all other similarly unsaturated carbinols.’