Patent ID: 7030156

Claim:
A compound of formula: wherein each R 16 is independently selected from the group consisting of an oxygen atom and CH 2 ; R 17 is CR 28 R 23 2 , wherein each R 23 is independently selected from the group consisting of a halogen atom, a hydrogen atom, a hydrocarbon group optionally substituted with one or more groups, an aromatic group optionally substituted with one or more groups, and an acyl group; with the proviso that at least one R 23 is a halogen atom, and R 28 is selected from the group consisting of R 23 and groups of the formulae: each R 18 is independently selected from the group consisting of a hydrogen atom, a halogen atom, and OH; and each R 19 and each R 20 are independently selected from the group consisting of a hydrogen atom, and a group of the formula: with the proviso that R 19 and R 20 are not both the group of the formula