Abstract: The present invention describes a stereospecific process for the isomerization of prochiral allyl amines into chiral enamines and imines, using Rh, Ir or Ru catalysts which carry chiral phosphine ligands derived from ferrocenes, which may be immobilized on a solid carrier, or from steroides. The process is in particular appropriate for the production of chiral citronellal, which can be obtained in optical purities of greater than 95%.

Abstract: Described herein are compounds of the formula ##STR1## wherein R represents a hydrogen atom or a methyl radical and X stands for a --CHO, or a --CN group, are useful as perfuming ingredients for preparing perfuming compositions and a variety of perfumed articles, to which they impart sandalwood-type odor notes, together with marine, ozone type odor characters, such that said compositions and articles thus acquire a "transparent" connotation. The aldehydes of formula (I) are also useful as starting products for the preparation of the corresponding fragrant alcohols and nitriles.

Abstract: The chiral isomers of 3,3-dimethyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol and, more particularly, the (-)-(1'R,2S,E)-3,3-dimethyl-5-(2',2',3'-trimethyl-3'-cyclopenten-1'-yl)-4- penten-2-ol and (+)-(1'S,2S,E)-3,3-dimethyl-5-(2',2',3'-trimethyl-3'-cyclopenten-1'-yl)-4- penten-2-ol, are useful as perfuming ingredients to impart sandalwood type odor notes to the perfuming compositions and perfumed articles into which they are incorporated.

Abstract: The invention relates to compounds of formula ##STR1## having a double bond in one of the positions indicated by the dotted lines. Compounds (I) are useful as perfuming ingredients for the preparation of perfuming compositions and perfuming articles, to which they impart sandalwood-animal notes.

Abstract: A process for the preparation of a polyunsaturated olefinic compound, i.e. undeca-1,3,5-triene, in its (3E,5Z) isomeric form, consisting of four consecutive steps starting from deca-1,4-diyne, is disclosed.Said process has the advantage of making it possible to obtain the desired isomer in its essentially pure form.

Abstract: 1,2-Dimethyl-4-(2',2',3'-trimethyl-3'-cyclopenten-1'-yl)-2-cyclohexen-1-ol is useful as a perfuming ingredient, for the preparation of perfuming compositions and perfumed articles to which it imparts woody-sandalwood type odor notes.

Abstract: Novel compounds of formula ##STR1## wherein the dotted lines indicate the location of a single or double bond, symbol R.sup.1 stands for a hydrogen atom or a methyl radical, symbol R.sup.2 represents a linear or branched, saturated or unsaturated, C.sub.1 to C.sub.4 alkyl radical, provided that R.sup.1 is not hydrogen when R.sup.2 represents a methyl or n-propyl radical and the ring is saturated. Compounds (Ia) are useful as perfuming ingredients.A process for their preparation is disclosed.

Abstract: A compound of formula ##STR1## wherein R.sup.1 represents a hydrogen atom or a saturated, linear or branched, alkyl radical, having from 1 to 4 carbon atoms, and R.sup.2 designates a lower alkyl radical, saturated or unsaturated, linear or branched;or any mixture containing a predominant amount of said compound (I), together with its isomer of formula ##STR2## wherein R.sup.1 and R.sup.2 are defined as above. Compounds (I) and their mixtures mentioned above develop odor notes of the woody-amber type and are therefore used as perfuming ingredients for the preparation of perfuming compositions and perfumed articles.A process for the preparation of compounds (I) and their mixtures is disclosed.

Abstract: New 4,4,5,8-tetramethyl-1-oxaspiro[2,5]octane. A process for its preparation starting from 2,2,3,6-tetramethyl-1-cyclohexanone is described.4,4,5,8-Tetramethyl-1-oxaspiro[2,5]octane is a useful raw material for the preparation of 2,2,3,6-tetramethyl-cyclohexane-carbaldehyde, a key intermediate for the synthesis of valuable fragrance ingredients.

Abstract: New 4,4,5,8-tetramethyl-1-oxaspiro[2.5]octane. A process for its preparation starting from 2,2,3,6-tetramethyl-1-cyclohexanone is described.4,4,5,8-Tetramethyl-1-oxaspiro[2.5]octane is a useful raw material for the preparation of 2,2,3,6-tetramethyl-cyclohexane-carbaldehyde, a key intermediate for the synthetis of valuable fragrance ingredients.

Abstract: The cycloaliphatic aldehydes of formula ##STR1## wherein R.sup.0, R.sup.1 and R.sup.2 represent independently a hydrogen atom or a lower alkyl from C.sub.1 to C.sub.6 and X stands for a group of formula ##STR2## wherein R.sup.3 and R.sup.4 represent independenly a lower alkyl radical from C.sub.1 to C.sub.3 and R.sup.5 represents a lower alkyl radical or hydrogen, provided that R.sup.1, R.sup.3 and R.sup.4 do not represent simulataneously a methyl radical whenever R.sup.0 and R.sup.2 represent each a hydrogen atom, are prepared from enol esters of formula ##STR3## wherein the wavy line stands for a --C--O-- bond of cis or trans configuration, Y represents an acyl group or P(O)(OR).sub.2, wherein R stands for a lower alkyl monovalent radical or an aryl, and Z defines a group of formula ##STR4## wherein R.sup.3, R.sup.4 and R.sup.5 are defined as above, by cyclisation carried out by means of an acidic cyclisation agent.