Abstract: Provided is a lubricating oil additive which is able to impart friction adjusting performance and rust preventing performance which are essential for practical use of a lubricant composed of an ionic liquid, and is dissolved or dispersed in the ionic liquid even when blended with the ionic liquid, and thus, does not inhibit performances as a base oil of the ionic liquid. The present invention relates to a synthetic lubricant including a fluorine atom-containing ionic liquid (A) as a main component, wherein the synthetic lubricant contains an imidazolium phosphate ester salt (B).

Abstract: The object of the present invention is to provide a synthetic lubrication oil which shows low viscosity, is excellent in viscosity properties at high temperature and shows stable lubricating properties in a wide range of temperature. The synthetic lubricating oil is one comprising an ionic liquid containing an organic cation selected from the group consisting of an imidazolium cation, a pyridinium cation, a quaternary ammonium cation and a quaternary phosphonium cation and a bis(fluorosulfonyl)imide anion, and one comprising an ionic liquid composition which comprises an ionic liquid (A) containing a 1-ethyl-3-methylimidazolium cation and an ionic liquid (B1) containing a 1-methyl-3-propylimidazolium cation and/or an ionic liquid (B2) containing a 1-methyl-3-isopropylimidazolium cation.

Abstract: A process for preparing an optically active .gamma.-halo-.beta.-hydroxybutyric acid ester in high yields which comprises subjecting a .gamma.-haloacetoacetic acid ester to the action of a microorganism selected from genus Saccharomyces under an anaerobic condition. When the .gamma.-haloacetoacetic acid ester is subjected to the action of the microorganism in the presence of a ketal, the yield and optical purity can be further increased.