Abstract: New phenolic compounds of formula (I) R=C3-C17 dialkoxymethyl group, 1,3-dioxolan-2-yl group optionally substituted on peaks 4 and/or 5 by one or more C1-C8 alkyls or 1,3-dioxan-2-yl group optionally substituted on peaks 4 and/or 5 and/or 6 by one or more C1-C8 alkyls. n=1, 2 or 3, the group or groups are in o and/or p position of the OH of the cycle m=from 0 to 4-n, X=functional group such as OH or Hal or C1-C8 alkyl or alkoxy group or C5-C12 aryl group and optionally 1 or 2 heteroatoms such as N or O, or carboxy or —CO—Y group where Y=C1-C8 alkyl or alkoxy or amido or amino or thiol group, on condition that at least one of the ortho or para positions of the phenolic cycle is substituted by a hydrogen, and their salts with the alkali metals, alkaline-earth metals and amines.