Depigmenting keratin materials utilizing dithiolane compounds

A method for depigmenting, lightening and/or bleaching a keratin substrate, comprising topically applying thereon a thus effective amount of a cosmetic composition which comprises at least one compound of formula (I):

• in which:
• Y is O, NR1 or S
• R1 is a hydrogen atom;
• a saturated linear C1-C20 or branched C3-C20 or unsaturated C2-C20 alkyl hydrocarbon-based radical;
• a phenyl radical optionally substituted with one or more hydroxyl groups and/or with one or more C1-C8 alkoxy radicals;
• R is a hydrogen atom;
• or a saturated linear C1-C20 or branched C3-C20 or unsaturated C2-C20 alkyl hydrocarbon-based radical, or a phenyl radical optionally substituted with one or more hydroxyl groups and/or with one or more C1-C8 alkoxy radicals, or a saturated C1-C8 alkyl radical containing a phenyl substituent optionally substituted with one or more hydroxyl groups and/or with one or more C1-C8 alkoxy radicals;
• R optionally bears one or more substituents selected from the group consisting of OR2, SR2, NR2R3, COOR2 in which:
• R2 is a hydrogen atom or a saturated linear C1-C5 or branched C3-C5 or unsaturated C2-C5 hydrocarbon-based radical, or a phenyl radical;
• R3 is a hydrogen atom, a saturated linear C1-C5 or branched C3-C5 or unsaturated C2-C5 hydrocarbon-based radical, a phenyl radical, or an acetyl radical;
• with the proviso that when Y═NR1, R and R1 may together form a ring member selected from the group consisting of pyrrolidine, pyrroline, piperidine, piperazine, morpholine, thiomorpholine and azepine;
• n=0 or 1 or 2;
• or a salt, chelate, solvate or optional isomer thereof, formulated into a topically applicable, physiologically acceptable medium therefor.