EP1519931A2

EP1519931A2 - Chiral 3,4-dihydro-2h-pyran compounds

Info

Publication number: EP1519931A2
Application number: EP03761553A
Authority: EP
Inventors: Robert Parker; Frank Prechtl; Sylke Haremza; Frank Meyer; Volkmar Vill; Gunnar Gesekus
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2002-07-01
Filing date: 2003-06-30
Publication date: 2005-04-06
Also published as: AU2003250860A8; US7258902B2; WO2004002979A3; WO2004002979A2; AU2003250860A1; DE10229530A1; JP2005538969A; CN100400532C; CN1735606A; US20050230660A1

Abstract

The invention relates to chiral 3,4-dihydro-2H-pyran compounds, to diastereomers thereof, and to the use of these compounds as chiral dopants for liquid crystal systems. The invention also relates to non-polymerizable or polymerizable liquid crystal compositions, which contain at least one inventive chiral 3,4-dihydro-2H-pyran compound, to the use of these non-polymerizable or polymerizable liquid crystal compositions for producing optical components, to the use of the polymerizable liquid crystal compositions for imprinting or coating substrates, for producing dispersions and emulsions, films or pigments, and to these optical elements, imprinted or coated substrates, dispersions and emulsions, films and pigments.

Description

Chiral 3, 4-dihydro-2H-pyran compounds

description

The invention relates to chiral 3, 4-dihydro-2ff-pyran compounds and their Diastereo ere and the use of these compounds as chiral dopants for liquid-crystalline systems.

The invention further relates to non-polymerizable or polymerizable liquid-crystalline compositions which contain at least one chiral 3, 4-dihydro-2iϊ-pyran compound according to the invention, the use of these non-polymerizable or polymerizable liquid-crystalline compositions for the production of optical components, the use of the polymerizable liquid-crystalline compositions for printing or coating substrates, for producing dispersions and emulsions, films or pigments, and also such optical components, printed or coated substrates, dispersions and emulsions, films and pigments.

Cholesteric liquid crystal mixtures are usually made using a liquid-crystalline (nematic) base material and one or more optically active dopants. As a result, the optical properties of the mixture can be varied by simply changing the ratio of nematic to dopant. However, to avoid possible negative influences of the dopant on the other properties of the nematic host system, e.g. In order to keep phase behavior and width small, dopants are particularly in demand, which cause large changes in the optical properties even in small additions.

Chiral dopants for liquid-crystalline phases are known in large numbers from the scientific and patent literature. It is all the more surprising that chiral 3, 4-dihydro-2iT-pyran compounds have obviously not yet been considered as dopants for liquid-crystalline systems.

The object of the present invention was to provide further chiral compounds which are suitable for the production of cholesteric-liquid-crystalline compositions, have a relatively high twisting power and accordingly already have a large influence on the optical properties of the liquid-crystalline host system in comparatively small amounts , This object was achieved according to the invention by the chiral compounds of the general formula I.

and their diastereomers solved.

Here mean

R ¹ and R ² independently of one another groupings p_yl_ _A l_γ2_ _M _ _Y 3_ ( _A 2) _ιn _γ4_

With

A ¹ , A ² spacers with one to 30 carbon atoms,

M mesogenic group,

Y ¹ , Y ² , Y ³ , Y ⁴ single chemical bond, -0-, -S-, -C0-, -C0-0-, -O-CO-, -CO-N (R) -, - (R ) N-C0 -, - 0-C0-0-, -O-CO-N (R) -, - (R) N-CO-O- or - (R) N-CO-N (R) -,

R is hydrogen or -CC ₄ alkyl,

P is hydrogen, -CC-alkyl, a polymerizable or suitable group for polymerization or a residue which carries a polymerizable or suitable group for polymerization, and

m values of 0 or 1,

where the variables A ¹ , A ² , Y ¹ , Y ² , γ3, γ4, M, P and the index m of the groupings R ¹ and R ^{2 can be the} same or different, with the proviso that in the event that the Index m is 0, at least one of the variables Y ³ and Y ⁴ adjacent to A ² means a chemical bond.

Spacers A ¹ and A ² are all groups known to the person skilled in the art for this purpose. The spacers generally contain one to 30, preferably one to 12, particularly preferably one to six carbon atoms and consist of predominantly linear aliphatic groups. You can in the chain, for example by not Adjacent oxygen or sulfur atoms or I ino or alkyl imino groups such as methylimino groups can be interrupted. Fluorine, chlorine, bromine, cyano, methyl and ethyl can also be used as substituents for the spacer chain.

Representative spacers are for example:

- (CH ₂ ) _U -, - (CH ₂ CH ₂ 0) _v CH ₂ CH ₂ -, -CHCH ₂ SCH ₂ CH ₂ -, -CH ₂ CH ₂ NHCH ₂ CH-,

CH ₃ CH ₃ CH ₃ CH _{3 cl}

-CH ₂ CH ₂ INF-CH ₂ CH-, - (CH ₂ CHO) _w CH ₂ CH-, - (CH ₂ ) ₆ CH- or -CH ₂ CH ₂ CH-,

where u is 1 to 30, preferably 1 to 12, v is 1 to 14, preferably 1 to 5, and w is 1 to 9, preferably 1 to 3.

Preferred spacers are ethylene, propylene, n-butylene, n-pentylene and n-hexylene.

All groups suitable as such for the person skilled in the art can serve as mesogenic groups M.

In particular, there are mesogenic groups of the formula Ia

(-TY ⁵ ) _r -T- Ia

into what the variables mean

T divalent saturated or unsaturated carbo- or heterocyclic radicals

Y ⁵ -chemical single bond, -0-, -S-, -CO-, -C0-0-, -O-CO-,

-CO-N (R) -, - (R) N-CO -, - 0-CO-0-, -O-CO-N (R) -, - (R) N-CO-O- or - ( R) N-CO-N (R) - and

r values of 0, 1, 2 or 3, where for r> 0 both the variables T and the variables Y ⁵ can be the same or different from one another.

The radicals T can by fluorine, chlorine, bromine, cyano, hydroxyl, foryl, nitro, C ₁ -C ₂₀ -alkyl, C 1 -C ₂₀ alkoxy, C ₁ -C ₂₀ alkoxycarbonyl, C ₁ -C ₂ o-monoalkylaminocarbonyl , Cχ-Co-alkylcarbonyl, Cι-C ₀ alkyl carbonyloxy or Cι-C ₀ alkylcarbonylamino substituted ring systems. Preferred radicals T are:

and

Examples of suitable mesogenic groups M are:

Other possible mesogenic groups M obey the following formulas:

The (unsubstituted) mesogenic groups shown above can, of course, in accordance with the examples given above for possible radicals T, also by fluorine, chlorine, bromine, cyano, hydroxyl, formyl, nitro, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkoxy , -C-C ₂₀ alkoxycarbonyl, -C-C ₂₀ monoalkylaminocarbonyl, Cχ-Co-alkylcarbonyl, Cι-Co-alkylcarbonyloxy or Cχ-C ₂ o-alkylcarbonylamino substituted. Preferred substituents are, above all, short-chain aliphatic radicals such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl and alkoxy, alkoxycarbonyl, alkylcarbonyl, Alkylcarbonyloxy, alkylcarbonylamino and monoalkylaminocarbonyl radicals which contain these alkyl groups.

Preferred 3,4-dihydro-2iϊ-pyran compounds are those in which, in the mesogenic group of the formula Ia of the groups R ¹ and R ^2, the index r independently of one another assumes the values 0 or 1.

In particular, the mesogenic groups of the groupings R ¹ and R ² can be mentioned

In addition, as previously mentioned, these mesogenic groups can additionally be substituted. As C 1 -C ₂ alkyl for P are branched or unbranched C 1 -C 4 alkyl chains, for example methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1st , 1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2, 2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1, 1-dimethylpropyl, 1,2 -Dirnethylpropyl, 1-Methylpentyl, 2-Methylpentyl, 3-Methylpentyl, -Methylpentyl, 1,1-Dirnethylbutyl, 1,2-Dirnethylbutyl, 1,3-Dirnethylbutyl, 2,2-Dimethylbutyl, 2, 3-Dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1, 1, 2-trimethylpropyl, 1,2, 2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl and n-dodecyl.

Preferred alkyl for P are the branched or unbranched Ci-C _o -alkyl chains, such as methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dirnethyl - ethyl, n-pentyl, 1-methylb tyl, 2-methylbutyl, 3-methylbutyl, 2, 2-dimethylpropyl, 1-ethylpropyl, n-hexyl.

P can be considered as a polymerizable or suitable group for polymerisation or as a group bearing a polymerisable or suitable group for polymerisation (hereinafter such groups or groups are simply referred to as "reactive groups"):

-N = C = 0, -N = C = S, -OC≡≡N, -C00H, -OH or NH ₂ , where the radicals R ³ to R ^{5 can be the} same or different and are hydrogen or C 1 -C ₄ - Alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

From the polymerizable groups, the cyanates can trimerize spontaneously to cyanurates. The other groups mentioned require further compounds with complementary reactive groups for the polymerization. For example, isocyanates with alcohols polymerize to urethanes and with a in to urea derivatives.

The same applies to thiiranes and aziridines. Carboxyl groups can be condensed to polyesters and polyamides. The maleimido group is particularly suitable for radical copolymerization with olefinic compounds, such as styrene or

Compounds containing styrene structural elements.

The complementary reactive radicals, together with the reactive radicals corresponding to them, can be present in one and the same 3, 4-dihydro-2.ϊ-pyran compound according to the invention (so that this compound can also polymerize with itself) or in a further 3,4-dihydro-2H-pyran compound according to the invention. However, these complementary reactive radicals can, together with the corresponding reactive radicals, be in one and the same (auxiliary) compounds or in further such (auxiliary) compounds.

As a polymerizable group, the acrylate, methacrylate and vinyl radicals are particularly noteworthy.

According to the invention, the compounds of the formula I and their preferred embodiments are used as chiral dopants for liquid-crystalline systems. The term "liquid-crystalline systems" is not limited to systems in which one or more constituents already have liquid-crystalline properties per se (in the temperature range of interest) and which are also present in the system, but rather systems in which they are to be understood is manifested only by mixing the components or only by adding the chiral compounds (s) according to the invention to liquid-crystalline behavior (eg lyotropic systems). It should also be noted here that the compounds according to the invention need not themselves already have liquid-crystalline behavior.

Also claimed are liquid-crystalline and polymerizable liquid-crystalline compositions which contain at least one chiral compound of the formula I or a preferred embodiment.

The liquid-crystalline compositions here mean in particular non-polymerizable compositions which are not capable of forming polymerization or condensation products under customary conditions. These compositions can be mixed, for example, by mixing suitable, commercially available, liquid-crystalline materials, such as those used for active LC layers in display technology, with one or more of the compounds according to the invention. produce gene. In the latter, P in formula I corresponds accordingly to hydrogen or Cχ-Cι-alkyl.

According to the invention, the use of these (non-polymerizable) liquid-crystalline compositions for the production of optical components, such as e.g. LCDs, claimed. Optical components obtained in this way are also claimed according to the invention.

The present invention further relates to polymerizable liquid-crystalline compositions. These are to be understood in particular as those compositions in which at least one of the constituents is capable of forming polymerization or condensation products under customary conditions.

Depending on the number of reactive residues in the constituents of these compositions, the desired degree of polymerization, crosslinking and / or condensation can be set after the polymerization or condensation has taken place. In such compositions, the compounds of the formula I according to the invention have at least one, preferably two reactive radicals P in the groups R ¹ and / or R ² . These compositions can easily be prepared by mixing suitable polymerizable, liquid-crystalline materials with one or more of the compounds according to the invention. Suitable polymerizable, liquid-crystalline compounds are described, for example, in WO 95/22586, 95/24454, 95/24455, 96/04351, 96/24647, 97/00600, 97/34862 and 98/47979 and in German Offenlegungsschrift 198 35 730 described and correspond essentially to the schematic structure PYAYMYAYP, in which the variables P, Y, A and M have meanings similar to the variables P, Y ¹ to Y ⁴ , A ¹ , A ² and M in formula I.

According to the invention, the use of these polymerizable liquid-crystalline compositions for the production of optical components, such as e.g. Polarizers or filters claimed.

The present invention also relates to those optical components which have been obtained using these polymerizable liquid-crystalline compositions according to the invention.

According to the invention, the polymerizable liquid-crystalline compositions claimed are used for printing or coating substrates. Here these compositions other additives. Additives selected from the group consisting of photoinitiators, reactive diluents and diluents, additives selected from the group consisting of defoamers and deaerators, lubricants and leveling aids, thermosetting or radiation-curing aids, substrate wetting aids, wetting and dispersing aids, hydrophobizing agents are suitable as such , Adhesion promoters and auxiliaries for improving the scratch resistance, additives selected from the group consisting of dyes and pigments and additives selected from the group consisting of light, heat and / or oxidation stabilizers.

The chemical-physical nature of these additives is described in detail in WO 00/47694. It also describes liquid-crystalline mixtures in which the polymerizable liquid-crystalline compositions according to the invention, if appropriate in a mixture with the additives mentioned above, are also to be addressed. The polymerizable liquid-crystalline compositions claimed in the present application can be used as printing and coating agents for substrates, if appropriate in a mixture with said additives, correspondingly as stated in WO 00/47694.

Within the scope of the present invention, further printed or coated substrates are claimed which have been produced using the polymerizable compositions according to the invention, optionally in a mixture with the aforementioned additives.

In addition to paper and cardboard products, for example for tote bags, magazines, brochures, gift packaging and packaging materials for consumer, luxury and luxury goods, films such as for decorative and non-decorative packaging purposes, as well as textiles of any kind and leather are also suitable as such substrates ,

Other substrates are also goods of (entertainment) electronics, such as MC, MD, DVD and video recorders, televisions, radios, telephones / cell phones etc. and EDP devices, goods from the leisure, sports , Household and game sectors, such as bicycles, children's vehicles, skis, snowboards and surfboards, inline skaters and roller skates and ice skates, and household appliances. In addition, such substrates also include writing utensils and spectacle frames. Other substrates are also found in the construction sector, such as building walls or window panes. In the latter case, a functional effect may also be desired in addition to a decorative one. It is thus possible to create multiple layers on the window material, the individual layers of which have different chemical-physical properties. Are individual layers of the polymerizable liquid-crystalline compositions of opposite twist (by using one enantiomer and its optical antipode as a dopant according to the present invention) or individual layers of cross-linked cholesteric liquid-crystalline compositions of the same pitch but different pitch and thus different reflection properties (by using different Concentrations of dopant according to the present invention) applied, so specific can

Wavelengths or wavelength ranges of the light spectrum are reflected. In this way, for example, an IR or UV reflecting window coating is possible. For this aspect of the compositions according to the invention, especially thermal insulation coatings, reference is also made to the document WO 99/19267.

In the context of the present invention, the use of the polymerizable liquid-crystalline compositions according to the invention for the production of dispersions and emulsions, which are preferably based on water, is also claimed. For the production of such dispersions and emulsions, reference is made to the documents WO 96/02597 and WO 98/47979, in which the production of dispersions and emulsions using liquid-crystalline materials is described.

The present invention therefore relates to dispersions and emulsions which have been prepared using the polymerizable liquid-crystalline compositions according to the invention. These dispersions and emulsions can also be used for printing and coating substrates, as have already been described above by way of example.

The present invention furthermore relates to the use of the polymerizable liquid-crystalline compositions according to the invention for the production of films. Such films are to be understood in particular as self-supporting layers as are obtained by polymerizing the compositions. These films can be located on substrates or underlays which are designed in such a way that they can be easily detached and transferred to other substrates or underlays for permanent retention by suitable measures. Such Films can be used, for example, in the field of film coating and in laminating processes.

Accordingly, the present invention also relates to films which have been produced using the polymerizable liquid-crystalline compositions according to the invention.

The use of the polymerizable liquid-crystalline compositions according to the invention for the production of pigments is also claimed.

The production of such pigments is known and is described in detail, for example, in WO 99/11733. In addition, the shape and size of the pigments can also be produced using printing techniques or with the aid of nets, in the interstices of which the polymerizable composition is located. The subsequent polymerization or condensation of the liquid-crystalline composition is followed by detachment or removal from the substrate or from the network. These procedures are described in detail in the documents WO 96/02597, WO 97/27251, WO 97/27252 and EP 0 931 110.

The polymerizable liquid-crystalline compositions are converted with the aid of their reactive groups and, depending on their chemical nature, by condensation or radical or ionic polymerization processes which can be started by photochemical reactions, into polymers with a frozen liquid-crystalline order structure.

These pigments can be single-layer (homogeneous) or have a multi-layer structure. However, the latter pigments can usually only be produced if coating processes are used, in which several layers are successively produced one above the other and then subjected to mechanical comminution.

The present invention thus also relates to pigments produced from such polymerizable liquid-crystalline compositions according to the invention. Examples

A. General:

5 A.I. Chromatographic methods:

All reactions were followed by thin layer chromatography on silica gel finished films (Merck, Kieselgel 60, F ₂₅₄ ). The detection was carried out by UV absorption and spraying with a 10 10% ethanolic sulfuric acid and subsequent heat treatment.

Column chromatographic separations were carried out by means of flash chromatography on silica gel (230-400 mesh, particle size 0.040-0.063 mm,

15 Merck) with the specified distilled solvents. Anhydrous solvents were obtained from the Fluka company under the appropriate quality designation or dried by conventional methods and stored over freshly activated molecular sieves.

20

A.II. Analytical information:

Optical rotations: Perkin-Elmer polarimeter PE 243 or 341 for the sodium D line (589 nm), 10 cm cuvette length, concentration specification [c] = [g / 100 ml].

NMR spectroscopy: Bruker-AMX 200, Bruker-AMX 400 or DRX 500 in automation mode; 1st order evaluation. TMS was used as the internal standard or calibrated to the characteristic solvent signals.

Phase transformations (uncorrected): Olympus BH polarizing microscope with Mettler FP 82 heating table; liquid crystalline phase assignment due to characteristic textures.

35

HTP measurements (HTP: helical twisting water): lens variant of the Grandjean-Cano method, 0.5-6 mol% in ZLI 1840 (commercially available liquid-crystalline product from Merck); Specification of the HTP: 15 ° C below the clearing point. The HTP sign was determined using contact mixtures with cholesteric mesophas known sign by observing the nematic compensation line.

The abbreviations K, Ch, BP, N, S _A and I when determining the phase conversions stand for crystalline, cholesteric, blue phase, nematic, smectic A phase and isotropic respectively. A. III. General labor regulations (AAV):

AAV-1: esterification using the DCC method (DCC: N, N'-dicyclohexylcarbodiimide)

A solution of the alcohol or phenol (1.0 eq.), The carboxylic acid (1.1 eq.), The N, N'-dicyclohexylcarbodiimide (from Aldrich, purity 99%; approx. 1.1 - 1.7 eq .) and catalytic amounts of 4-pyrrolidinopyridine (Aldrich, purity 98%; approx. 0.01 eq.) are stirred in anhydrous dichloroethane until the reaction is complete. The N, N'-dicyclohexylurea formed is filtered off, the solvent is removed in vacuo, and the residue is purified as described.

AAV-2: Basic deacetylation with sodium methoxide

1 mmol each of the ester is dissolved in 5 ml of absolute methanol and a catalytic amount of sodium methoxide is added until the reaction is basic. After stirring at room temperature for 12 h, the mixture is neutralized with an acidic ion exchanger (Amberlite IR 120 H ⁺ form), filtered and the solvent is removed in vacuo.

AAV-3: esterification using the imidazolid method

For each equivalent of the hydroxy function to be esterified, one equivalent of N, N'-carbonyldiimidazole (from Aldrich, purity 99%) and one equivalent of the carboxylic acid in 2-5 ml of anhydrous N, N-dimethylformamide under a nitrogen atmosphere with CO ₂ evolution become light heated. Depending on the carboxylic acid, the reaction is complete after 5-120 minutes (solution 1). A solution 2 of 1 mmol of the _: alcohol in 2 ml of anhydrous N, N-dimethylformamide is then mixed with a catalytic amount of sodium at room temperature under a nitrogen atmosphere. After the sodium has completely dissolved, this solution is added dropwise to the initially prepared solution 1 of the carboxylic acid imidazolide under a nitrogen atmosphere and, if appropriate, heated to 40 ° C. to a maximum of 80 ° C. with stirring, depending on the reaction rate. After the end of the reaction, the solvent is removed in vacuo and the crude product is purified as indicated in each case.

AAV-4: Basic deacetylation with sodium carbonate

1 g of the ester is dissolved in 10 ml of absolute methanol and 1 g of sodium carbonate is added. After stirring for 3-12 h at room temperature, the sodium carbonate is filtered off using Celite ^® (Aldrich), the solution with an acidic ion exchanger (A - berlite® IR 120 H ⁺ shape; Aldrich) neutralized and the solvent removed in vacuo.

AAV-5: esterification of alcohols and phenols with carboxylic acid chlorides

A catalytic amount of 4-pyrrolidinopyridine (approx. 0.01 eq.) And 1 equivalent of the alcohol or phenol are dissolved under a nitrogen atmosphere in an anhydrous solution of dichloromethane and pyridine 1: 1 (2 ml solution per 1 mmol of the alcohol or phenol ) given. With stirring, 1.05 equivalents of the carboxylic acid chloride per hydroxy function (dissolved in as little anhydrous dichloromethane as possible) are slowly added dropwise to the batch. After the end of the reaction, the reaction mixture is diluted with dichloromethane and neutralized with 2 M hydrochloric acid solution and washed once with distilled water. The organic phase is dried over magnesium sulfate and concentrated in vacuo. The raw product is cleaned as indicated.

AAV-6: Selective deprotection of phenylacetates with guanidine hydrochloride

1 mmol of guanidine hydrochloride (Aldrich, purity 99%) is dissolved in 10 ml of anhydrous methanol and stirred with 0.9 equivalents of sodium methoxide for five minutes at room temperature. The mixture is added to a solution of 1 mmol of the phenylacetate in 50 ml of methanol, and the resulting methyl acetate is removed at 40 ° C. and 270 mbar on a rotary evaporator together with the solvent. The processing can be carried out according to two methods:

Method 1: The reaction mixture, which is evaporated to dryness in vacuo, is mixed with 50 ml of hydrochloric acid and dichloromethane and stirred until no undissolved residues are left. The organic phase is separated off, the aqueous phase is extracted several times with dichloromethane, the combined organic phases are dried over magnesium sulfate and the solvent is removed in vacuo.

Method 2: The reaction mixture, which was evaporated to dryness in vacuo, is dissolved in 10 ml of 1,2-dimethoxyethane, acidified with 1 M hydrochloric acid and slowly added to 100 ml of distilled water with stirring. The resulting precipitate is filtered off, dissolved in dichloromethane, dried over magnesium sulfate and the solvent removed in vacuo. B. Synthesis of pentose series glycals

Scheme 1:

Ac ₂ O / Na0Ac

93% ΔT 52%

l) HBr / HOAc

66% 2) Zn / HOAc

95% Na ₂ CO ₃ / CH ₃ OH 94%

D-Xylal (3) D-Arabinal (.

B. I. Synthesis of D-xylal (3)

B.I.L. Synthesis of 1,2,3,4-tetra-O-acetyl-ß-D-xylopyranose (1)

To a stirred suspension of 43 g of sodium acetate in 236 ml of acetic anhydride, 50.0 g (0.33 mol) of D-xylose (Aldrich, purity 99%) are added in portions at 115 ° C. after removing the heat so that the Temperature does not rise above 118 ° C. The mixture is then stirred at 115 ° C. for two hours. After cooling to room temperature, the reaction mixture is poured onto 1 liter of ice water, 500 ml of dichloromethane are added and the mixture is stirred for 12 hours. The aqueous phase is separated off and three times extracted with 250 ml dichloromethane each. The combined organic phases are washed neutral with saturated sodium bicarbonate solution, washed with 250 ml of water and dried over magnesium sulfate. Then activated carbon is added, after stirring for a quarter of an hour the activated carbon is filtered off and the solvent is removed.

Molecular formula: -C ₃ H ₁₈ 0 ₉ (MW = 318.28 g / mol), yield: 98 g (0.31 mol, 93%);

Characterization: colorless crystals; [α] _D ²⁰ = -20.5 (c = 0.5, CHC1 ₃ ); Mp: 127 ° C; Structure was confirmed by ⁱ H-NMR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (125 MHz, CDCI ₃ ).

B.I.2. Synthesis of 3, -Di-O-acetyl-D-xylal (2)

56.00 g (0.176 mol) of compound 1 are dissolved in 15 ml of acetic anhydride and 15 ml of glacial acetic acid. After cooling to 0 ° C., 100 ml of hydrogen bromide / glacial acetic acid (33%) are added dropwise and the mixture is stirred at room temperature for 2 hours. The crude acetobromoxylose solution is added dropwise at 0 ° C. to a reduction mixture of 47.48 g of sodium acetate trihydrate, 300 ml of acetone, 80 ml of distilled water, 80 ml of acetic acid and 250 g of activated zinc powder over the course of 1.5 hours. The temperature must not exceed 10 ° C. After the addition has ended, the mixture is stirred for a further 1 h at 0 ° C. and then for a further 1.25 h at room temperature. After the zinc has been filtered off, the filter residue is washed with an acetic acid / water mixture (1: 1). The solution is then extracted once with ice water and three times with cold chloroform and the combined organic phases are neutralized with sodium hydrogen carbonate. The solution is dried over magnesium sulfate and the solvent is removed in vacuo. The product is purified by flash chromatography using silica gel filtration (petroleum ether (50/70) / diethyl ether, 3: 1).

Molecular formula: C _s H ₁₂ 0 ₅ (MW = 200.19 g / mol), yield: 23.47 g (0.117 mol, 66%);

Characterization: colorless solid; [α] _D ²⁰ = -316.7 (c = 1.0, CHCI ₃ ); Mp: 37-39 ° C; Structure was confirmed by 1H-NMR (400 MHz, CDCI3) and ¹³ C-NMR (100 MHz, CDCI ₃ ).

B .1.3. Synthesis of D-xylal (3)

Preparation according to AAV-4: 4.00 g of compound 2 (20 mmol) and 4.00 g of anhydrous sodium carbonate in 50 ml of methanol. Molecular formula: C ₅ H ₈ 0 ₃ (MW = 116.12 g / mol), yield: 2.23 g (19 mmol, 95%);

Characterization: yellowish solid; [α] _D ²⁰ = -249.8 (c = 0.5, CHC1 ₃ ); M.p .: 46.0-49.1 ° C; Structure was confirmed by ⁱ H-NMR (400 MHz, CD ₃ OD) and ¹³ C-NMR (100 MHz, CD ₃ OD).

B.II. Synthesis of D-Arabinal (9)

B.II.l. Synthesis of 1,2,3,4-tetra-O-acetyl-α-D-arabinopyranose (7)

50.00 g (0.33 mol) of D-arabinose (from Aldrich, purity 99%) are added in portions at 115 ° C. to a stirred suspension of 43 g of sodium acetate in 236 ml of acetic anhydride after the heat has been removed, that the temperature does not rise above 118 ° C. The mixture is then stirred at 115 ° C. for two hours. After the Ab. cooling to room temperature, the reaction mixture is poured onto one liter of ice-water, 500 ml of dichloromethane are added and the mixture is stirred for 12 hours. The aqueous phase is separated off and extracted three times with 250 ml of dichloromethane each time. The combined organic phases are washed neutral with saturated sodium bicarbonate solution, washed with 250 ml of water and dried over magnesium sulfate. The solvent is then removed in vacuo. Purification: multiple recrystallization from ethanol.

Molecular formula: C ₁₃ H ₁₈ O ₉ (MW = 318.28 g / mol), yield: 55.03 g (0.17 mol, 52%);

Characterization: colorless crystals; [α] _D ²⁰ = -43.1 (c = 0.5, CHCI ₃ ); Mp: 94.7 ° C; Structure was confirmed by ⁱ H-NMR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (100 MHz, CDCI ₃ ).

B.II.2. Synthesis of 3,4-di-O-acetyl-D-arabinal (8)

55.00 g (0.173 mol) of compound 7 are dissolved in 15 ml of acetic anhydride and 15 ml of glacial acetic acid. After cooling to 0 ° C., 100 ml of hydrobromic acid / glacial acetic acid (33%) are added dropwise and the mixture is stirred at room temperature for 2 hours. The crude acetobromarabinose solution is added dropwise at 0 ° C. to a reduction mixture of 47.48 g of sodium acetate trihydrate, 300 ml of acetone, 80 ml of distilled water, 80 ml of acetic acid and 250 g of activated zinc powder over the course of 1.5 hours. The temperature must not exceed 10 ° C. After the addition is complete, the mixture is stirred at 0 ° C. for 1 h and then at room temperature for a further 1.25 h. After filtering off the zinc, the filter residue is washed with a vinegar acid / water mixture (1: 1) washed. The solution is then extracted once with ice water and three times with cold chloroform and the combined organic phases are neutralized with sodium bicarbonate. The solution is dried over magnesium sulfate and the solvent is removed. The product is purified by flash chromatography using column filtration (petroleum ether (50/70) / diethyl ether, 3: 1).

Molecular formula: C ₉ Hι ₂ 0 ₅ (MW = 200.19 g / mol), yield: 11.58 g (58 mmol, 34%);

Characterization: viscous syrup; [cc] _D ²⁰ = +265.2 (c = 1.2, CHC1 ₃ ); Structure was confirmed by ^ H NMR (400 MHz, CDCI ₃ ) and ¹³ C NMR (125 MHz, CDCI ₃ ).

B.II.3. Synthesis of D-Arabinal (9)

Preparation according to AAV-2: 5.70 g (28.5 mmol) of compound 8 in 55 ml of anhydrous methanol.

Molecular formula: CsH ₈ 0 ₃ (MW = 116.12 g / mol), yield: 3.10 g (26.7 mmol, 94%);

Characterization: colorless crystals; [α] n ²⁰ = +238.7 (c = 0.5, CH ₃ OH)? Mp: 80.7 ° C; Structure was confirmed by ⁱ H-NMR (400 MHz, CD ₃ OD) and ¹³ C-NMR (100 MHz, CD ₃ OD).

Synthesis of dopants according to the invention based on D-xylal (3) and D-arabinal (9)

(4a) R = Hi ₅ C ₇ 0-Ph-Ph-CO (10a): R = H ₃ CO-Ph-CO (4b) R = Hi ₅ C ₇ 0-Ch-Ph-CO (10b): R = H ₁₇ C ₈ 0-Ph-COO-Ph-CO (4c) R = H ₃ CO-Ph-CO

(4d): R = H ₁₇ C ₈ 0-Ph-COO-Ph-CO

(Ph: 1,4-phenylene; Ch: trans-1,4-cyclohexylene) CI synthesis of dopants based on D-xylal (3)

C.1.1. Synthesis of 3, -Di-O- (4 '' -heptyloxybiphenyl-4 '-carbo- 5 nyl) -D-xylal (4a)

Representation according to AAV-3. To solution 1 with 686 mg (2.10 mmol)

4 '' heptyloxybiphenyl-4 'carboxylic acid (synthesis instructions: S.-L.

Wu et al., Mol. Cryst. Liq. Cryst. Be. Technol. Sect. A 1995,

10 264, 29-50) and 341 mg (2.10 mmol) of N, N'-carbonyldiimidazole in 4 ml of anhydrous N, N-dimethylformamide (reaction temperature: 40 ° C.), solution 2 with 122 mg (1.05 mmol) the compound 3 in 2 ml of N, N-dimethylformamide was added dropwise, reaction temperature 70 ° C. Cleaning: The concentrated raw product is washed with distilled water

15 added, filtered, the residue washed once with water, dried in vacuo and recrystallized from ethanol.

Molecular formula: C ₄₅ H ₅₂ 0 ₇ (MW = 704.91 g / mol), yield: 240 mg (0.34 mmol, 32%);

20

Characterization: colorless solid; [CC] _D ²⁰ = -286.0 (c = 0.5,

CHC1 ₃ ); K 155.7-156.6 (Ch 147.0 BP) I; Ber. : C 76.68 H 7.44. :

C 76.49 H 7.41; Structure was confirmed by ⁱ -H-NMR (400 MHz, CDCI ₃₎ and ¹³ C-NMR (100 MHz, CDCI _3).

25

C.I.2. Synthesis of 3,4-di-O- (4'- (rans-4 '' -heptylcyclohe-xy1) -benzoy1) -D-xy1al (b)

Representation according to AAV-3. To solution 1 with 630 mg (2.08 mmol) 30 4 '- (trans-4' 'heptylcyclohexyl) benzoic acid (synthesis instructions: JC Liang, L. Chen, Mol. Cryst. Liq. Cryst. 1989, 167, 253 -258) and 340 mg (2.10 mmol) of N, N'-carbonyldiimidazole in 4 ml of anhydrous N, N-dimethylformamide (reaction temperature: 40 ° C.) solution 2 with 123 mg (1.06 mmol) of compound 3 in 2 ml of N, N-dime-35-thylformamide were added dropwise, reaction temperature 65 ° C. Purification: The concentrated crude product is mixed with distilled water, filtered, the residue washed once with water, dried in vacuo and recrystallized from ethanol.

0 Molecular formula: C ₄₅ H ₆₄ θ ₅ (MW = 685.00 g / mol), yield: 210 mg (0.31 mmol, 29%);

Characterization: colorless solid; [] n ²⁰ = -218.9 (c = 0.5, CHCI ₃ ); K 125.4 (Ch <100) I; Calc .: C 78.90 H 9.42, Found: C 78.95 H 5 9.51; Structure was confirmed by ^ H NMR (400 MHz, CDCI ₃ ) and ¹³ C NMR (100 MHz, CDCI ₃ ). CI3. Synthesis of 3,4-di-O- (4'-methoxybenzoyl) -D-xylal (4c)

Preparation according to AAV-5 with 118 mg (1.02 mmol) of compound 3 in 2 ml solution of dichloromethane and pyridine 1: 1 and 182 mg (1.07 mmol) 4-methoxybenzoic acid chloride (Aldrich, purity 99%). The crude product is purified by column chromatography on silica gel (mobile phase: petroleum ether (50/70) / ethyl acetate, 3: 1).

Molecular formula: C ₂ ιH ₂ o0 ₇ (MW = 384.39 g / mol), yield: 260 mg (0.68 mmol, 67%);

Characterization: colorless solid; [α] _D ²⁰ = -372.0 (c = 0.5, CHC1 ₃ ); M.p .: 140.9 ° C; Calc .: C 65.62 H 5.24, Found: C 65.65 H 5.27; Structure was confirmed by ⁱ H-MR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (100 MHz, CDCI ₃ ).

C.I.4. Synthesis of 3,4-di-O- (4'- (4 '' octyloxybenzoyloxy) -benzoyl) -D-xylal (4d)

C.I.4.1. Synthesis of 4- (benzoyloxy) benzoic acid

17.3 ml (20.90 g, 149 mmol) of benzoyl chloride (Aldrich, purity 99%) are stirred vigorously into an ice-cooled solution of 20.00 g (145 mmol) of 4-hydroxybenzoic acid (Aldrich, Rein- unit 99%) and 12.00 g (300 mmol) of sodium hydroxide in 300 ml of distilled water and 30 ml of acetone were added dropwise over a period of 30 minutes. After a further 30 minutes, the mixture is acidified with concentrated hydrochloric acid and diluted with 750 ml of distilled water. The resulting white precipitate is filtered off and recrystallized from methanol / ethanol / ethyl acetate (450 ml + 225 ml + 300 ml).

Molecular formula: C ₁₄ H ₁₀ O ₄ (MW = 242.23 g / mol), yield: 27.01 g (112 mmol, 77%);

Characterization: colorless crystals; M.p .: 222.6 ° C; Structure was confirmed by ⁱ H-NMR (400 MHz, CDCI ₃ ).

C.I.4.2. Synthesis of 4- (benzoyloxy) benzoic acid chloride

10.00 g (41.3 mmol) of 4- (benzoyloxy) benzoic acid and a drop of N, N-dimethylformamide are refluxed in 40 ml of thionyl chloride with stirring until no more gas evolution takes place. The excess thionyl chloride is largely removed by distillation under reduced pressure and the residue which remains is codistilled twice with petroleum ether (50/70) in vacuo to remove it completely. The cleaning is done by recrystallization tion from 150 ml of petroleum ether (50/70) / ethyl acetate 2: 1, the crystals are washed with 4 ml of petroleum ether (50/70).

Molecular formula: C ₁₄ H ₉ O ₃ CI (MW = 260.68 g / mol), yield: 7.23 g (27.7 mmol, 67%);

Characterization: colorless crystals; Mp: 134.0 ° C; Structure was confirmed by ^ H NMR (400 MHz, benzene-d ₆ ).

C.I.4.3. Synthesis of 3,4-di-O- (4'-benzoyloxy-benzoyl) -D-xylal

Preparation according to AAV-5 with 594 mg (5.12 mmol) of compound 3 in 5 ml of anhydrous pyridine and 2.998 g (11.50 mmol) of 4- (benzoyloxy) benzoic acid chloride in 10 ml of anhydrous dichloromethane. The crude product is purified by column chromatography on silica gel (mobile phase: chloroform).

Molecular formula: C ₃₃ H ₂₄ O ₉ (MW = 564.55 g / mol), yield: 333 mg (0.59 mmol, 12%);

Characterization: colorless crystals; [α] _D ²⁰ = -285.0 (c = 0.2,

CHC1 ₃ ); K 139.2 (Ch 127.9) I; Ber. : C 70, 21 H 4, 28, found. : C 70, 26

H 4.28; Structure was determined by ¹ H NMR (400 MHz, CDCI ₃ ) and ¹³ C NMR

(100 MHz, CDCI ₃ ) confirmed.

C.I.4.4. Synthesis of 3,4-di-O- (4-acetyloxy-benzoyl) -D-xylal

Preparation according to AAV-5 with 3.00 g (25.8 mmol) of compound 3 in 130 ml dichloromethane and 40 ml anhydrous pyridine and 11.10 g (55.9 mmol) 4-acetyloxybenzoic acid chloride (synthesis instructions: E. Nomura et al ., J. Org. Chem. 2001, 66, 8030-8036) in 10 ml of anhydrous dichloromethane. The crude product is recrystallized from 320 nil ethanol / toluene (7: 1).

Molecular formula: C ₂₃ H ₂ o0 ₉ (MW = 440.41 g / mol), yield: 9.34 g (21.2 mmol, 82%);

Characterization: colorless crystals; [α] _D ²⁰ = -310.1 (c = 0.6, CHCI ₃ ); Mp: 145.6 ° C; Calc .: C 62.73 H 4.58, Found: C 62.48 H 4.50; Structure was confirmed by iH-NMR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (100 MHz, CDC1 ₃ ).

C.I.4.5. Synthesis of 3,4-di-O- (4 '-hydroxybenzoyl) -D-xylal

Preparation according to AAV-6 with 5.00 g (11.3 mmol) 3,4-di-O- (4-acetyl-oxy-benzoyl) -D-xylal in 250 ml anhydrous methanol and 2.10 g (22, 0 mmol) guanidine hydrochloride and 1.07 g (19.8 mmol) sodium methanolate in 100 ml of anhydrous methanol. Processing: Method 1.

Molecular formula: CιgHi ₆ θ ₇ (MW = 356.33 g / mol), yield: 3.75 g (10.5 5 mmol, 93%);

Characterization: colorless crystals; [α] _D ²⁰ = -363.8 (c = 0.5, CH ₃ OH); Mp: 161.2 ° C; Calc .: C 64.04 H 4.53, Found: C 63.67 H 4.54; Structure was confirmed by ⁱ H-NMR (400 MHz, acetone-d ₆ ) and ¹³ C-NMR 10 (100 MHz, acetone-d ₆ ).

C.I.4.6. Synthesis of 3, -di-O- (4'- (4 '' octyloxybenzoyloxy) -benzoyl) -D-xylal (d)

15 Illustration according to AAV-1 with 400 mg (1.12 mmol) 3, 4-di-O- (4 '-hydroxybenzoyl) -D-xylal, 609 mg (2.95 mmol) DCC and 626 mg (2nd , 50 mmol) 4-octyloxybenzoic acid in 40 ml anhydrous dichloromethane. The crude product is recrystallized from 70 ml of isopropanol.

20 Molecular formula: C _4S H ₅₅ 0n (MW = 820.98 g / mol), yield: 625 mg (0.76 mmol, 68%);

Characterization: colorless crystals; [α] n ²⁰ = -223.8 (c = 0.6, CHCI ₃ ); K 120.9 Ch Dec .; Calc .: C 71.69 H 6.88, Found: C 71.37 H 25 6.96; Structure was confirmed by ⁱ H-R (400 MHz, CDCI ₃ ) and ¹³ C-NMR (125 MHz, CDCI ₃ ).

C.II. Synthesis of dopants according to the invention based on D-arabinal (9) 30

C. II .1. Synthesis of 3, -Di-O- (4 '-methoxybenzoyl) -D-arabinal (10a)

Preparation according to AAV-5 with 3.00 g (25.8 mmol) of compound 9 in 35 30 ml of anhydrous pyridine and 10.30 g (60.4 mmol) of 4-methoxybenzoic acid chloride in 5 ml of anhydrous dichloromethane. The crude product is purified by column chromatography on silica gel (Running ^•: petroleum ether (50/70) / ethyl acetate, 7: 1).

40 molecular formula: C ₂ ιH ₂ o0 (MW = 384.39 g / mol), yield: 5.33 g (13.9 mmol, 54%);

Characterization: colorless syrup; [α] _D ²⁰ = +281.1 (c = 0.5, CHC1 ₃ ); Calc .: C 65.62 H 5.24, Found: C 65.71 H 5.30; Structure was confirmed by -H-NMR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (100 MHz, CDCI ₃ ). C. II .2. Synthesis of 3,4-di-O- (4 '- (4''octyloxybenzoyloxy) benzoyl) -D-arabinal (10b)

C. II.2.1. Synthesis of 3,4-di-O- (4'-acetoxybenzoyl) -D-arabinal

Preparation according to AAV-5 with 400 mg (3.44 mmol) of compound 9 in 20 ml dichloromethane and 7 ml anhydrous pyridine and 1.50 g (7.55 mmol) 4-acetyloxybenzoic acid chloride in 1.5 ml anhydrous dichloromethane.

Molecular formula: C ₂₃ H ₂₀ O ₉ (MW = 440.41 g / mol), yield: 1.436 g (3.26 mmol, 95%);

Characterization: colorless syrup; [CC] _D ²⁰ = +146.7 (c = 0.5, CHC1 ₃ ); Calc .: C 62.73 H 4.58, Found: C 62.72 H 4.53; Structure was confirmed by iH-NMR (400 MHz, CDCI ₃ ) and ¹³ C-NMR (125 MHz, CDCI ₃ ).

C. II .2.2. Synthesis of 3,4-di-O- ('-hydroxybenzoyl) -D-arabinal

Preparation according to AAV-6 with 1,200 g (2.72 mmol) 3, 4-di-O- (4 '-acetoxybenzoyl) -D-arabinal in 160 ml anhydrous methanol and 0.242 g (2.53 mmol) guanidine hydrochloride and 0.131 g (2.42 mmol) sodium methoxide in 20 ml anhydrous methanol. Processing: Method 1.

Molecular formula: Cι ₉ Hι ₆ 0 ₇ (MW = 356.33 g / mol), yield: 950 mg (2.67 mmol, 98%);

Characterization: colorless syrup; [α] _D ²⁰ = +108.6 (c = 0.7,

CHCI ₃ ); Calc .: C 64.04 H 4.53, Found: C 63.51 H 4.52; Structure was confirmed by -H-NMR (400 MHz, acetone-d ₆ ) and ¹³ C-NMR (100 MHz, acetone-d ₆ ).

C.II.2.3. Synthesis of 4-octyloxybenzoic acid

17.64 g (128 mmol) of 4-hydroxybenzoic acid (Aldrich, purity 99%) and 14.32 g (255 mmol) of potassium hydroxide are dissolved in 30 ml of distilled water and added to 260 ml of ethanol. After the addition of 33.0 g (29.7 ml, 0.17 mol) of 1-bromooctane (Aldrich company, purity 99%), the solution is heated to boiling with stirring for 24 hours. Another 14.32 g (255 mmol) of potassium hydroxide are then added and the mixture is heated to reflux with stirring for a further two hours. After the reaction mixture has cooled, the solvent is largely removed in vacuo, the residue in dist. Water absorbed and strongly acidified with 2 M hydrochloric acid solution. The residue is extracted with chloroform, dried over magnesium sulfate, concentrated and recrystallized from acetone.

Su menfor el: -C ₅ H ₂₂ 0 ₃ (MW = 250.34 g / mol), yield: 26.1 g (104 mmol, 81%);

Characterization: colorless crystal needles; K 101 SA 107 N 146 I; Structure was confirmed by ^ H NMR (400 MHz, CDC1 ₃ ).

C.II.2.4. Synthesis of 3,4-di-O- (4 '- (4' 'octyloxybenzoyloxy) benzoyl) -D-arabinal (10b)

Preparation according to AAV-1 with 0.788 g (2.21 mmol) 3, -Di-O- (4'-hydroxybenzoyl) -D-arabinal, 1.240 g (6.01 mmol) DCC and 1.127 g (4.50 mmol) 4-0ctyloxybenzoic acid in 80 ml anhydrous dichloromethane. The crude product is recrystallized from 40 ml of isopropanol.

Molecular formula: C 9H ₅ 6O ₁₁ (MW = 820.98 g / mol), yield: 1.227 g (1.49 mmol, 67%);

Characterization: colorless crystals; [α] _D ²⁰ = +138.5 (c = 0.6, CHCI ₃ ); Mp: 75.5-75.9 ° C; Calc .: C 71.69 H 6.88, Found: C 71.42 H 6.97; Structure was confirmed by ^ H NMR (400 MHz, CDCI ₃ ) and ¹³ C NMR (125 MHz, CDCI ₃ ).

D. Measurement of the HTP on selected dopants according to the invention

HTP values according to the in A.II. described procedure in ZLI 1840 determined. The values obtained are listed in the table below.

Claims

claims

1. Chiral compounds of the general formula I

and their diastereomers, in which mean

R ¹ and R ² independently of one another groupings PY ¹ -A ¹ -Y ² -MY ³ - (A ² ) _m -Y ⁴ -

With

A ¹ , A ² spacers with one to 30 carbon atoms,

M mesogenic group,

Y ¹ , Y ² , Y ³ , Y ⁴ single chemical bond, -0-, -S-, -C0-, -CO-O-, -0-C0-, -CO-N (R) -, - (R ) N-CO-, -O-CO-O-,

-O-CO-N (R) -, - (R) N-CO-O- or - (R) N-CO-N (R) -,

R is hydrogen or -CC ₄ alkyl,

P is hydrogen, C 1 -C 8 -alkyl, a polymerizable or suitable group for polymerisation or a radical which carries a polymerisable or suitable group for polymerisation, and

m values of 0 or 1,

where the variables A ¹ , A ² , Y ¹ , Y ² , Y ³ , Y ⁴ , M, P and the index m of the groupings R ¹ and R ^{2 can be the} same or different, with the proviso that for the case that the index m is 0, at least one of the variables Y ³ and Y ⁴ adjacent to A ² signifies a chemical bond.

2. Compounds according to claim 1, in which the mesogenic group M of the formula Ia

(-T-γΞ) _r -T- (Ia) corresponds where the variables mean

T divalent saturated or unsaturated carbo- or heterocyclic residues

Y ⁵ -chemical single bond, -0-, -S-, -C0-, -CO-0-, -O-CO-, -CO-N (R) -, - (R) N-CO -, - 0 -CO-0-, -O-CO-N (R) -, - (R) N-CO-O- or - (R) N-CO-N (R) - and

R is hydrogen or -CC ₄ alkyl,

Compounds according to Claim 2, in which, in the mesogenic group of the formula Ia of the groups R ¹ and R ^2, the index r independently of one another takes the values 0 or 1.

4. Compounds according to claim 2 or 3, in which T is selected from the group consisting of

5. Compounds according to one or more of claims 1 to 4, in which in the groups R ¹ and R ² m is in each case 0, Y ³ a chemical single bond and Y ⁴ -O-, -CO-O-, -0- CO-0-, or - (R) N-CO-O- corresponds, where the variables Y ⁴ can be the same or different from one another.

6. Use of compounds according to one or more of claims 1 to 5 as chiral dopants for liquid-crystalline systems.

5 7. Liquid-crystalline compositions containing at least one chiral compound of the general formula I according to one or more of claims 1 to 5.

8. Polymerizable liquid-crystalline compositions containing at least one chiral compound of the general

Formula I according to one or more of claims 1 to 5.

9. Use of compositions according to claim 7 or 8 for the production of optical components.

15

10 .. Optical components which have been produced using compositions according to claim 7 or 8.

11. Use of compositions according to claim 8 for printing or coating substrates.

12. Printed or coated substrates which have been produced using compositions according to claim 8.

25

13. Use of compositions according to claim 8 for the preparation of dispersions and emulsions.

14. Dispersions and emulsions which have been prepared using compositions according to claim 8.

15. Use of compositions according to claim 8 for the production of films.

16. Films made using compositions according to claim 8.

17. Use of compositions according to claim 8 for the production of pigments.

40

18. Pigments which have been prepared using compositions according to claim 8.

45