Patent ID: 7018685

Claim:
A compound of the formula (I) where X is C═O, Y is H or F R 1 and R 2 are the same or different and are each hydrogen, or are a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms where a) one or more nonadjacent and nonterminal CH 2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH 3 ) 2 —, and/or b) one CH 2 group may be replaced by —C═C—, cyclopropane-1,2-diyl or cyclobutane-1,3-diyl, and/or c) one or more hydrogen atoms may be replaced by F or Cl, and/or d) the terminal CH 3 group may be replaced by one of the following chiral groups (optically active or racemic): where R 3 is a straight-chain or branched alkyl radical having from 1 to 12 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 12 carbon atoms, in each of which one or more nonadjacent and nonterminal CH 2 groups may be replaced by —O— and/or one or more hydrogen atoms may be replaced by F or Cl, with the proviso where only one of R 1 and R 2 is a hydrogen, M 1 and M 2 are the same or different and are each —C(═O)—O—, —O—C(═O)—, —CH 2 —O—, —O—CH 2 —, —CF 2 —O—, —O—CF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —CH 2 —CH 2 —C(═O)—O—, —O—C(═O)—CH 2 —CH 2 —, —CH 2 —CH 2 —, —CF 2 —CF 2 —, —(CH 2 ) 4 — or a single bond, A 1 and A 2 are the same or different and are each 1,4-phenylene where one or two hydrogen atoms may be replaced by F, Cl or CN, pyridine-2,5-diyl where one hydrogen atom may be replaced by F, pyrimidine-2,5-diyl, 1,4-cyclohexylene where one or two hydrogen atoms may be replaced by CH 3 or F, 1-cyclohexene-1,4-diyl where one hydrogen atom may be replaced by CH 3 or F, or 1,3-dioxane-2,5-diyl, m and n are each independently 0 or 1, but in total not greater than 1.