Compounds for a controlled release of active molecules

A compound of the formula

• P—X—R (I)
• wherein:
• a) P represents a radical derived from an perfuming α,β-unsaturated ketone, aldehyde or carboxylic ester and is represented by formula
• in which R1 represents a hydrogen atom, a C1 to C6 alkoxyl radical or a C1 to C15 linear, cyclic or branched alkyl, alkenyl or alkadienyl radical, optionally substituted by up to four C1 to C4 alkyl groups;
• and
• R2, R3 and R4 represent a hydrogen atom, an aromatic ring or a C1 to C15 linear, cyclic or branched alkyl, alkenyl or alkadienyl radical, optionally substituted by up to four C1 to C4 alkyl groups;
• two, or three, of the groups R1 to R4 can be bonded together to form a saturated or unsaturated ring having 6 to 20 carbon atoms and including the carbon atom to which said R1, R2, R3 or R4 groups are bonded, this ring being optionally substituted by up to four C1 to C4 linear or branched alkyl or alkenyl groups or by one C3 to C9 cyclic alkyl or alkenyl groups;
• and
• b) X represents a sulfur atom and R represents a cyclic, linear or branched alkyl, alkenyl or alkadienyl C1-C5 hydrocarbon radical substituted with a Si(OR5)3 group, R5 representing a C1-C5 alkyl or alkenyl group;
• or
• X represents a OC(O)O functional group and R represents a cyclic, linear or branched alkyl, alkenyl or alkadienyl C1-C5 hydrocarbon radical optionally substituted with a Si(OR5)3 group, R5 representing a C1-C5 alkyl or alkenyl group;
• said compound of formula (I) being in the form of a pure diastereomer or stereoisomer or in the form of any mixture of said isomers.