Abstract: Novel 2,6,10,15,19,23-hexamethyltetracosa-11,13-diin-10,15-diol derivatives. Such derivatives are prepared by oxydative coupling of 3,7,11-trimethyldodeca-1-in-3-ol derivatives or by ethynylation of 6,10-dimethylundecan-2-on derivatives with diacetylene and used as starting materials for preparing squalane.

Abstract: A process for preparing a .gamma.-lactone derivative having the formula (I) ##EQU1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6, which may be the same or different, each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group which may be substituted with a halogen atom, and R.sup.1 and R.sup.2, and R.sup.5 and R.sup.6 may, when taken together with the carbon atom to which they are attached, form a cycloalkyl group having 4 to 7 carbon atoms, and R.sup.7 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 6 carbon atoms or a phenyl group which may be substituted with an alkyl group having 1 to 3 carbon atoms, which comprises reacting an allylic diol with an orthocarboxylic acid ester in the presence of an acidic catalyst.

Abstract: A process for preparing a bicyclic .gamma.-lactone represented by the formula (I) ##SPC1##wherein R represents a hydrogen atom or a straight or branched chain alkyl group having 1 to 4 carbon atoms and n is an integer of 1 to 6, which comprises condensing a cycloalkene diol compound represented by the formula (II) ##SPC2##wherein n is as defined above, with an orthocarboxylic acid ester represented by the formula (III)r--ch.sub.2 --c(or.sup.1).sub.3 (iii)wherein R is as defined above and R.sup.1 represents a straight or branched chain alkyl group having 1 to 4 carbon atoms, in the presence of an acidic catalyst.