Abstract: The invention concerns a method for preparing 4-hydroquinolines and/or tautomeric compounds. More particularly, the invention concerns 5,7-dichloro-4-quinolines and/or its tautomeric compounds. The method is characterized in that it consists in heating a 4-hydroquinolinecarboxylic acid, its derivatives or precursors, at a temperature not more than 200° C. in the presence of a base.

Abstract: The 4-hydroxyquinoline compounds and/or tautomers thereof, notably 4-hydroxy-5,7-dichchloroquinoline, are synthesized in very high yields by hydrolyzing/decarboxylating a 4-hydroxyquinolinecarboxylic acid ester in the presence of water, whether in liquid or vapor state, but in the absence of any catalyst for such reaction(s).

Abstract: The invention provides novel sulphonated chiral phosphines of the formula: ##STR1## in which R represents an alkyl radical, a cycloalkyl radical optionally substituted with an alkyl radical, a cycloalkylalkyl radical optionally substituted with an alkyl radical, a phenyl, phenylalkyl, binaphthyl or binaphthylalkyl radical, in which the alkyl, cycloalkyl, phenyl and binaphthyl radicals, and the alkyl portions of the other radicals, can be substituted by a radical of general formula: ##STR2## R.sub.1 represents an alkyl, cycloalkyl, phenyl, or phenylalkyl radical, Ar represents a phenyl or naphthyl radical, m.sup.+ represents a proton or alkali metal ion or alkaline earth metal ion, m=1 or 2, n=0, 1 or 2, p=1 or 2, (p+m) .ltoreq.3, and R and R.sub.1 can be chiral or achiral. These chiral phosphines form water-soluble metal complexes useful as catalysts in asymmetric organic synthesis.

Abstract: Neral or geranial are hydrogenated into optically active citronellal in the presence of a catalytic complex comprising a rhodium derivative and a chiral phosphine.