The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (Δe), which contains at least one compound selected from the group of compounds of the formula I, II A and II B and at least one compound of the formula I* in which R0, R1, R2, R1*, X1, X2, A1, A1*, A2*, Z1, Z1*, Z2*, L1*, L2*, p, q, v, m and m* are as defined in Claim 1, and to the use thereof for an active-matrix display based on the ECB, VA, PS-VA, FFS, PALC or IPS effect.

Liquid Crystalline Medium

The present invention provides methods and compositions comprising at least one perhydrolase enzyme for cleaning and other applications. In some embodiments, the present invention provides methods and compositions for generation of long chain peracids. Certain embodiments of the present invention find particular use in applications involving cleaning, bleaching and disinfecting.

Enzyme for the production of long chain peracid

Green chemistry development in fluorine science

C-Difluoromethylene-containing, C-trifluoromethyl and C-perfluoroalkyl carbohydrates. Synthesis by carbohydrate transformation or building block methods.

The syntheses of the chiral α,β-unsaturated lactones (+)-5, (−)-6, (+)-8, (+)-9, and (+)-10 have been efficiently achieved from readily available starting materials. The lactone (+)-5 has been synthesized in 7 steps from (R,R)-dimethyl tartrate (38–43% overall yield). The use of (+)-5 in formal syntheses of natural (+)-asperlin 4 and advanced intermediates for (+)-olguine 2 are also reported. The lactone (−)-6 has been prepared in 5 steps from (R)-malic acid (44–50% overall yield). It can be a useful precursor for the syntheses of branched chain and deoxy nucleoside analogues. The preparation of (−)-6 constitues formal syntheses of natural (+)-eldanolide 53 and the (+)-Geissman-Waiss lactone 54 (an intermediate for the syntheses of a variety of pyrrolizidine alkaloids). The lactones (+)-8, (+)-9 and (+)-10 have been synthesized from 3,4-di-O-acetyl-L-rhamnal 58. The highly diastereoselective transformations of (+)-9 and (+)-10, through sequential conjugate nucleophilic addition and enolate reaction, into densely functionalized chiral γ-lactones 12 are also reported.

Stereoselective syntheses and reactions of chiral oxygenated α,β-unsaturated-γ- and δ-lactones

The novel pyranose derivatives with a trifluoromethyl group were found to be excellent chiral dopants for ferroelectric liquid crystals, inducing large spontaneous polarization by their addition even in a small quantity. These materials showed some characteristic physical properties depending on their stereochemical relationship : thus, the corresponding cis isomers exhibited high ability in inducing large spontaneous polarization and quick response but lowered the upper limit of the temperature of the Sc phase. However, the same trend in the spontaneous polarization was observed for the compounds with trans stereochemistry, without lowering the transition temperature of SA to SC, of the host liquid crystal. MoFover, it was also proved that the adjustment of the helical pitch of the N* phase was readily carried out. Based on these results, we have succeeded in the development of the practical ferroelectric liquid crystalline compositions with good alignment and quick response.

Trifluoromethylated pyranose derivatives as the chiral dopant for ferroelectric liquid crystals

An optically active tetrahydropyran derivative represented by one of the following general formulae, a liquid crystal composition containing the derivative, and a liquid crystal device containing the composition are disclosed. The optically active tetrahydropyran derivative is a novel compound which is chemically stable, causes no coloring, has excellent optical stability, and shows a large spontaneous polarization and a quick response. The optically active tetrahydropyran derivative can show a more excellent quick response when it is used in a composition, and is useful as a component in a ferroelectric liquid crystal which induces a large spontaneous polarization. ##STR1##

Optically active tetrahydropyrane derivatives, liquid crystal composition and liquid crystal device containing the same

There is disclosed an optically active fluorine-containing compound represented by the general formula (I) ##STR1## wherein Rf is a fluoroalkyl group having 1 or 2 carbon atoms; R1, R2 and R3, independently of one another, are each a hydrogen atom, a straight or branched chain alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; and * is an asymmetric carbon atom. The above compound has a fluoroalkyl group with a remarkable electron-attracting property at the asymmetric carbon atom in the tetrahydropyran ring. It is exemplified by tetrahydro-6-trifluoromethyl-2-hexyloxy-4-methyl-5-hydroxypyran and expected to find a wide variety of useful applications as raw materials for an enzyme inhibitor, a bioactive substance, a carcinostatic, a ferroelectric liquid crystal, etc.

Optically active fluorine-containing compounds

A variety of pyranose derivatives with a trifluoromethyl group were synthesized and found to be excellent chiral dopants for ferroelectric liquid crystals. Relationships between molecular structures and induced ferroelectric properties were discussed.

Synthesis and Properties of Pyranose Derivatives with Trifluoromethyl Group Used as Chiral Dopants for Ferroelectric Liquid Crystals

PURPOSE: To obtain a ferroelectric liquid crystal composition in which the temperature range of a ferroelectric chiral smectic C phase is wide and which has an excellent response realized by virtue of the large spontaneous polarization, high-speed response, etc., of the chiral comprising or has heat stability by mixing a matrix liquid crystal comprising several bicyclic phenylpyrimidine compounds (a), a tricyclic phenylpyrimidine compound (b) and a phenyl benzoate derivative (c) with an optically active tetrahydropyrane derivative (d) as a specified chiral liquid crystal component. CONSTITUTION: This composition is prepared by mixing 0.1-30wt.% component (d) represented by formula I (wherein Rf is a 1 or 2C fluoroalkyl; R is a 3-20C alkyl; R to R are each H, a 1-15C alkyl or the like; X is -COO-, a single bond or the like; X is -OCO-, -CH2 O- or the like, X is -COO- or the like; X is -O- or the like; the carbon atom marked with * is an asymmetrical carbon atom; A and B are each a halogen or the like; and n is 0 or 1) with the components (a), such as one represented by formula II (wherein k and m are each 1-15), the component (b) such as one represented by formula III (wherein p and q are each 1-15), and the component (c) represented by formula IV (wherein a and b are each 1-15).

Masaaki Namekawa

Papers

Trifluoromethylated pyranose derivatives as the chiral dopant for ferroelectric liquid crystals

Optically active tetrahydropyrane derivatives, liquid crystal composition and liquid crystal device containing the same

Optically active fluorine-containing compounds

Synthesis and Properties of Pyranose Derivatives with Trifluoromethyl Group Used as Chiral Dopants for Ferroelectric Liquid Crystals

Ferroelectric liquid crystal composition and liquid crystal element