Patent ID: 7470820

Claim:
A compound of formula wherein R 1 , taken separately, are identical and represent an achiral Cl 1-10 linear, branched or cyclic alkyl or alkenyl group optionally substituted, or alternatively said two R 1 , taken together, represent a linear C 3 -C 10 alkanediyl or alkenediyl group optionally substituted; R 2 represents an achiral C 1-7 linear, branched or cyclic alkyl or alkenyl group optionally substituted or a phenyl or benzyl group optionally substituted; and R represents: a hydrogen atom, a group of formula Si (R 3 ) 3 , where R 3 representing a C 1-7 linear, branched or cyclic alkyl or alkenyl group or a phenyl group optionally substituted, a C 1 -C 10 sulfonyl group, or a C 1 -C 10 hydrocarbon group optionally comprising up to four heteroatoms selected from the group consisting of oxygen, nitrogen, silicium or sulfur, provided that said heteroatom is not directly bonded to the oxygen atom bearing said R group; and further with the substituents of R, R 1 and R 2 being one or two C 1-5 alkyl, alkoxy or cycloalkyl group.