Abstract: are prepared by single-stage reaction of alkoxydihydropyrans of the formula (II) with water and hydrogen in the presence of a catalyst comprising oxides of nickel, zirconium and copper. In the formulae (I) and (II), R, R′, R″, R′″ can be identical or different and are each hydrogen or a linear or branched saturated hydrocarbon radical having from 1 to 20 carbon atoms in which the hydrocarbon chain may contain O, S and N as heteroatoms and which may be monosubstituted or polysubstituted by hydroxy, thiol or amino groups or halogens.

Abstract: This invention concerns a method of substituting a chlorine atom for a predetermined hydrogen atom located within an organic compound which comprises contacting the organic compound containing the predetermined hydrogen atom with an esterifying agent comprising a pyridine ring or a substituted or fused ring derivative of a pyridine ring so as to produce an ester and treating the ester with a chlorinating agent so as to substitute the chlorine atom for the predetermined hydrogen atom. The ester comprises the pyridine ring or the substituted or fused ring derivative of the pyridine ring so positioned within the ester with respect to the predetermined hydrogen atom that a chlorine atom attached to the nitrogen atom of the pyridine ring or substituted or fused ring derivative of the pyridine ring reacts with the predetermined hydrogen atom.