Abstract: Sulphones useful for preparing polyenes have the formula: ##STR1## where the sulphonyl group replaces a hydrogen atom on carbon atom (a) or (b), R represents alkyl, aralkyl or aryl, optionally substituted, A and Q represent an optionally substituted hydrocarbon of 5n+1 carbon atoms (n is 1-5), methyl, optionally substituted by halogen, sulphide or sulphone, CH.sub.2 OH (or an ether or ester thereof), CHO (optionally protected), COOH (or an acid chloride, ester or nitrile thereof), with the proviso that when A represents a 2-(2,6,6-trimethylcyclohex-1-enyl) ethenyl radical, Q cannot represent --COOH or an ester thereof.

Abstract: A process for the preparation of .alpha.,.beta.-ethylenic aldehydes containing at least 7 carbon atoms by reacting an allyl alcohol with a dienoxytriorganosilane.

Abstract: Sulphones of the formula: ##STR1## in which R is a substituted or unsubstituted alkyl, alkylaryl, aralkyl, or aryl radical, A is a radical containing one or more isoprene units which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups, and which may be cyclic when the number of isoprene units is at least 2, and Q is hydrogen or a cyclic or acyclic hydrocarbon radical which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, and which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups are useful intermediates in the production of terpene compounds such as .beta.-carotene and canthaxanthine.

Abstract: Sulphones of the formula: ##STR1## in which R is a substituted or unsubstituted alkyl, alkylaryl, aralkyl, or aryl radical, A is a radical containing one or more isoprene units which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups, and which may be cyclic when the number of isoprene units is at least 2, and Q is hydrogen or a cyclic or acyclic hydrocarbon radical which is saturated, unsaturated, or of the conjugated or unconjugated polyene type, and which is unsubstituted or substituted by one or more functional groups, halogen atoms or alkyl groups are useful intermediates in the production of terpene compounds such as .beta.-carotene and canthaxanthine.

Abstract: Carotene compounds e.g. .beta.-carotene, are prepared by reacting a sulphone Ret--SO.sub.2 --R, in which Ret represents retinyl or substituted retinyl and R represents a hydrocarbon radical, in the presence of an alkaline reagent with an ester Ret-X, in which X represents an acid residue, and then desulphonating the product, for example with an alkaline reagent.

Abstract: The addition of a free metal of group VIII of the Periodic Table or of one of its oxides or hydroxides to acrylonitrile heated under a hydrogen pressure of 1 to 50 bars in the presence of a ruthenium derivative as catalyst improves the rate of conversion of the acrylonitrile into 1,4-dicyanobutenes and/or adiponitrile.

Abstract: Sulphones of formula QSO.sub.2 CH.sub.2 CY=CY.sub.1 CH.sub.2 CHRR.sub.1 wherein one of Y and Y.sub.1 is hydrogen the other methyl, R and R.sub.1 are CHO, COR.sub.2, COOH, COOR.sub.3, CONR.sub.5 R.sub.5, CN, SO.sub.2 R.sub.4, SO.sub.3 R.sub.5 and NO.sub.2, wherein R.sub.2 -R.sub.5 are alkyl or aryl and R.sub.5 can be hydrogen, and Q is alkyl, substituted alkyl, aryl, aralkyl or alkaryl or optionally substituted, optionally unsaturated terpene of 5n carbon atoms (n being 1-9), but excluding 2- or 3-methylbutadienyl and 2-butadienylmethyl, are intermediates for preparing terpenes.

Abstract: 7-Alkoxydihydrocitronellals (and their homologues) and their acetals useful as perfumes are prepared from citronellal (or homologues thereof) by reaction with ammonia or a primary or secondary amine, followed by treatment of the product with an alkanol in the presence of a strong acid and then neutralization of the reaction mixture.

Abstract: Ethylenic carbonyl compounds are obtained by heating an .alpha.-ethylenic tertiary alcohol with oxygen and 0.0001 to 5% by weight, based on the alcohol, of a catalyst comprising a compound of a transition metal of Groups V, VI or VII of the Periodic Table.