Abstract: The invention concerns a refrigerant composition which comprises a chlorine-free hydrofluorocarbon based refrigerant and, mixed with the refrigerant, a lubricant comprising a polyol ester. According to the invention the polyol ester comprises an ester of 2-butyl-2-ethyl-1,3-propane diol, the carboxylic acid residue of which is derived from a linear or branched C4 . . . C8-carboxylic acid or an anhydride thereof, or it is derived from a mixture of linear or branched C4 . . . C18-carboxylic acids or anhydrides thereof. The present invention also concerns novel complex esters of 2-butyl-2-ethyl-1,3-propanediol, which contain residues of mono- or bivalent carboxylic acids. The novel esters exhibit good solubility in fluorinated hydrocarbons and excellent lubricating properties.

Abstract: The present invention relates to a process for the preparation of diols of the general formula (I) ##STR1## and monoesters thereof of the general formula (II) ##STR2## and the general formula (III) ##STR3## wherein R.sub.1 and R.sub.2 are the same of different groups and each denotes a lower alkyl group having 1 to 4 carbon atoms, preferably a methyl group. The process of this invention comprises condensing in a multi-phase reaction environment an aldehyde containing a hydrogen atom in the alpha position and having the general formula (IV) ##STR4## wherein R.sub.1 and R.sub.2 having the meaning given above, in the presence of a catalytic system consisting of a phase transferring catalyst and an alkaline substance.