JPH0692952A - Optically active lactone derivative, liquid crystal composition containing the same and liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as a ferroelectric liquid crystal display material especially excellent in responsiveness and memory characteristics. CONSTITUTION:The compound is expressed by formula I (R<1> is (substituted) alkyl; X is a single bond, O, S, etc.; Y is OCO, COO, etc.; Z is COO, Ch2O; R<2> is alkyl; ring A and Ring B are 1,4-phenylene, pyridine-2,5-diyl etc.; (m) is 0 or 1; (n) is 1 or 2). E.g. (2S,4R) and (2R,4R)-2-(4-hydroxyphenyl)-2methyl-4- decanolide. A compound of formula I can be obtained by subjecting a compound of formula II to react with a carboxylic acid of formula III in the presence of a condensing agent (e.g. dicyclohexyl carbodiimide). A liquid crystal compound capable of responsing at high speed in a wide range of temperature can be obtained, as a large spontaneous polarization is induced by adding only a small amount of the compound of formula I in a mother liquid crystal composition. It us colorless and excellent in water resistance, light resistance and especially chemical stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optically active lactone derivative and a liquid crystal material, and more particularly to a ferroelectric liquid crystal display material having excellent responsiveness and memory property.

[0002]

2. Description of the Related Art A liquid crystal display device has excellent characteristics (low voltage operation, low power consumption, thin display, and can be used in a bright place without eye strain.
Etc.), is currently widely used. However, in the TN type, which is the most common display method, the response is extremely slow compared to other light emitting display methods such as CRT, and the display memory (memory effect) when the applied electric field is cut off is Since it cannot be obtained, there are many restrictions in application to moving screens such as an optical shutter that requires a high-speed response, a printer head, or a television that requires time-division driving, and it cannot be said that it is a suitable display method.

Recently, a display method using a ferroelectric liquid crystal has been reported, and according to this, a TN type liquid crystal display of 100-1 is used.
Since a high-speed response of 000 times and a memory effect can be obtained, it is expected as a next-generation liquid crystal display device, and research and development are being actively conducted at present.

Ferroelectric liquid crystals belong to the tilt-type chiral smectic phase as the liquid crystal phase, but the chiral smectic C (hereinafter abbreviated as Sc ^* ) phase has the lowest viscosity and is practically the most desirable. . A large number of liquid crystal compounds exhibiting the Sc ^* phase have already been synthesized and studied, but the following conditions must be satisfied for use as a ferroelectric liquid crystal device. That is, (a) it exhibits a Sc ^* phase in a wide temperature range including room temperature, and (b) it has an appropriate phase series on the high temperature side of the Sc ^* phase in order to obtain good orientation, and its spiral pitch is large. It is necessary to satisfy the following conditions: (c) having an appropriate tilt angle, (d) having a small viscosity, (e) having a certain degree of spontaneous polarization, and (f) exhibiting a fast response. However, a compound that satisfies these conditions alone is not known. Therefore, it is necessary to mix several or more kinds of compounds and use them as a liquid crystal composition showing a Sc ^* phase (hereinafter, abbreviated as Sc ^* liquid crystal composition).

As a method for preparing the Sc ^* liquid crystal composition, a dopant composed of an optically active compound is added as a so-called chiral dopant to a base liquid crystal composed of an achiral compound and exhibiting a smectic C (hereinafter abbreviated as Sc) phase. The method is the most common. This is because according to this method, a composition having a lower viscosity can be obtained and a high-speed response is possible. The compound used as the chiral dopant does not necessarily need to exhibit the Sc * phase and does not even have to exhibit the liquid crystal phase by itself, but it can induce sufficient spontaneous polarization in the liquid crystal composition with a small amount of addition, or induce as the chiral dopant. It is necessary to exhibit properties such as a sufficiently large spiral pitch.

In order to induce a large spontaneous polarization as a chiral dopant, it is necessary that a group having a strong dipole moment is fixed as close as possible to the central skeleton (core) and asymmetric carbon of the compound molecule. This is already known. Based on such an idea, the inventors of the present invention formula (III)

[0007]

[Chemical 3]

(In the formula, Mes represents a liquid crystal skeleton and R represents an alkyl group.) An optically active lactone derivative represented by the formula is synthesized. It has been found that it becomes possible to prepare a responsive Sc ^* liquid crystal composition. (Page 16 of the 16th Liquid Crystal Conference, and JP-A-2-286673.
Issue)

[0009]

However, the compound represented by the above general formula (III) is an asymmetric carbon having a relatively active hydrogen atom at the α-position of the carbonyl group of the lactone ring, and therefore acts as a base. Therefore, there is a problem in that the absolute configuration is likely to be isomerized to form a diastereomer mixture.

The problem to be solved by the present invention is to provide an optically active compound which induces a large spontaneous polarization by adding a small amount as a chiral dopant to a host liquid crystal and enables a fast response. It is to provide a material for a dielectric liquid crystal display.

[0011]

In order to solve the above problems, the present invention provides the following general formula (I):

[Chemical 4]

(In the formula, R ¹ represents a fluorine atom, a chlorine atom, a cyano group or an alkyl group having 1 to 18 carbon atoms, which may be substituted by an alkoxyl group having 1 to 10 carbon atoms, and is preferably Represents an alkyl group having 2 to 12 carbon atoms, X is a single bond, -O-, -S-, -CO.
-, -COO-, -OCO-, -OCOO-, preferably a single bond or -O-, wherein ring A and ring B are each independently substituted by 1 or 2 fluorine atoms. Optionally 1,4-phenylene group, trans-1,4-cyclohexylene group, pyridine-2,
5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, pyridazine-3,6-diyl group or 1,3-dioxane-2,5-diyl group, preferably 1,4-phenylene group or trans-
Represents a 1,4-cyclohexylene group. Y is -COO
-, - OCO -, - CH 2 O -, - OCH 2 -, - CH 2
CH ₂ —, —C≡C—, or a single bond, and m is 0
Or 1 but preferably 0 and Z is --CO
O- or represents a -CH ₂ O-, preferably -CO
Represents O-, n represents 1 or 2, and preferably 1
R ² represents a linear or branched alkyl group having 1 to 18 carbon atoms, preferably 1 carbon atom
It represents a linear alkyl group of 10 to 10, and the asymmetric carbon atoms at the 2-position and 4-position of the lactone ring are independently in the (R) or (S) configuration. The present invention provides an optically active lactone derivative represented by

The present invention also provides the following intermediates of the general formula (II) as synthetic intermediates for the compounds of the general formula (I).

[0014]

[Chemical 5]

An optically active lactone derivative represented by the formula: wherein n and R ² have the same meaning as in formula (I).

The present invention further provides a liquid crystal composition using the optically active lactone derivative represented by the general formula (I).

The liquid crystal composition according to the present invention contains at least one of the compounds represented by the above general formula (I) as a constituent component, and is mainly used for a ferroelectric liquid crystal display device. At least one of the compounds represented by the general formula (I) is used as a part or all of the chiral dopant in the matrix liquid crystal exhibiting the Sc phase as a component.
A c ^* liquid crystal composition is suitable.

Further, by adding a small amount of the compound represented by the general formula (I) of the present invention to a nematic liquid crystal, TN
The liquid crystal can be used to prevent so-called reverse domains, or to be used as STN liquid crystal.

The compound of the present invention represented by the general formula (I) can be produced according to the following production method.

When Z represents --COO-- in the general formula (I), the optically active compound represented by the general formula (II) and the general formula (IV)

[0021]

[Chemical 6]

(Wherein R ¹ , X, ring A, ring B, Y, and m have the same meanings as in formula (I)) and dicarboxylic acid such as dicyclohexylcarbodiimide (DCC). The compound represented by the general formula (I) can be easily produced by reacting in the presence of a condensing agent.

Alternatively, it can also be produced by introducing a carboxylic acid represented by the general formula (IV) into an acid chloride and then reacting it with a compound represented by the general formula (II) in the presence of a base such as pyridine.

When Z represents --CH ₂ O-- in the general formula (I), the compound represented by the general formula (II) is reacted with the general formula (V) in the presence of a base.

[0025]

[Chemical 7]

(Wherein R ¹ , X, ring A, ring B, Y and m have the same meanings as in formula (I), W is chlorine, bromine,
It represents a leaving group such as iodine or p-toluenesulfonyloxy group. ) It can be produced by reacting with a compound represented by.

The optically active lactone derivative represented by the general formula (II) is a novel compound and can be produced as follows.

That is, the general formula (VI)

[0029]

[Chemical 8]

(Wherein R ³ represents a lower alkyl group such as a methyl group and n represents 1 or 2) and a phenylpropanoic acid derivative represented by the following general formula ( VII)

[0031]

[Chemical 9]

(In the formula, R ² has the same meaning as in formula (I).) After the reaction with the optically active oxirane, the ring is closed with an acid such as p-toluenesulfonic acid to give a compound of the general formula ( VIII)

[0033]

[Chemical 10]

An optically active lactone derivative represented by the formula (wherein R ³ and n have the same meaning as in formula (VI) and R ² has the same meaning as in formula (VIII)) can be obtained.

Then, the compound of the general formula (II) can be obtained by dealkylating this with aluminum chloride-dimethyl sulfide or the like.

Most of the compounds represented by the general formula (IV), the general formula (V) or the general formula (VI) are already known and can be obtained by a usual synthetic chemical method. Further, some of the optically active oxirane derivatives represented by the general formula (VII) are commercially available, and non-commercially available derivatives can be easily synthesized from commercially available optically active epichlorohydrin.

The compounds represented by the general formula (I) of the present invention can be obtained as described above. Specific compounds belonging to these compounds include phase transition temperatures such as melting points and infrared absorption spectra ( IR), nuclear magnetic resonance spectrum (N
It can be confirmed by means such as MR) and mass spectrum (MS).

Table 1 shows examples of the compounds represented by the general formula (I) thus obtained.

[0039]

[Table 1] (In the table, Cr represents a crystalline phase and I represents an isotropic liquid phase.)

One of the excellent characteristics of the compound represented by the general formula (I) is that it can induce a sufficiently large spontaneous polarization. For example, in the Sc ^* liquid crystal composition obtained by adding only 2% by weight to the matrix liquid crystal exhibiting the Sc phase, the Ps value at 25 ° C. is 1.47 nC / cm ² although the compounds shown in the examples below are added. , Which is most commonly used as a chiral source in liquid crystals (S) -2
-Sc ^* liquid crystal compound derived from methylbutanol, eg 4
It can be seen that the spontaneous polarization of-[(S) -2-methylbutoxy] phenyl 4-decyloxybenzoate is very large as compared with the case where the spontaneous polarization is the same alone without addition to the host liquid crystal. Therefore, if about 1% by weight or more is added to the non-chiral matrix liquid crystal, it becomes possible to induce spontaneous polarization to an extent sufficient for high-speed response.

In the compound of the present invention represented by the general formula (I), asymmetric carbon atoms are present at the 2-position and 4-position of the lactone ring. The asymmetric carbon at the 2-position corresponds to the α-position of the carbonyl group, but in the compound represented by the general formula (I) of the present invention, it is substituted with a methyl group and becomes a quaternary carbon. not exist. This point is a big difference from the compound represented by the general formula (III) which is a known compound of the present invention represented by the general formula (I). Therefore, it is very stable against bases and the like, and the absolute configuration of the asymmetric carbon at the 2-position does not isomerize.

As described above, the compound of the present invention represented by the general formula (I) is preferably used by adding it to the liquid crystal composition rather than using it alone. The resulting liquid crystal composition contains at least one optically active compound represented by the general formula (I) and, if necessary, a chiral dopant composed of another optically active compound, and is added to another liquid crystal compound or liquid crystal composition. In addition to that. Particularly when used as a ferroelectric liquid crystal display device, a composition added to a non-chiral matrix liquid crystal composition showing a Sc phase as a main component is desirable. Since the compound represented by the general formula (I) is capable of inducing a sufficiently large spontaneous polarization, a ferroelectric Sc ^* composition capable of high-speed response can be obtained by adding about 1% by weight or more to the matrix liquid crystal. it can.

Many of the compounds represented by the general formula (I) do not exhibit a liquid crystal phase by themselves, but by adding a small amount as a chiral dopant to another liquid crystal material, the temperature range of the liquid crystal phase, particularly the Sc ^* phase is narrowed. There is little to do.

Sc used in a host liquid crystal to which the compound of the present invention represented by the general formula (I) is added as a dopant
Examples of the compound exhibiting a phase (hereinafter abbreviated as Sc compound) include the following general formula (A)

[0045]

[Chemical 11]

(In the formula, R ^a and R ^b represent a linear or branched alkyl group, an alkoxyl group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, which may be the same or different from each other. .) And a general formula (B).

[0047]

[Chemical 12]

A pyrimidine compound represented by the formula (wherein R ^a and R ^b have the same meaning as in the general formula (A)) can be given.

The general formula (C) including the general formulas (A) and (B) is also included.

[0050]

[Chemical 13]

(In the formula, R ^a and R ^b have the same meanings as in formula (A), and ring L and ring M are 1,4-phenylene group, 1,4-cyclohexylene group, and
Pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, pyridazine-
It represents a 3,6-diyl group, a 1,3-dioxane-2,5-diyl group or a halogen-substituted product thereof, which may be the same or different, and Z ^a is —COO.
-, - OCO -, - CH 2 O -, - OCH 2 -, - CH 2
CH ₂ —, —C≡C— or a single bond. The compound represented by () can be used for the same purpose.

For the purpose of expanding the temperature range of the Sc phase to a high temperature range, the general formula (D)

[0053]

[Chemical 14]

(Wherein R ^a and R ^b have the same meanings as in formula (A), and ring L, ring M and ring N have the same meanings as ring L and ring M in formula (C). Represent
They may be the same or different from each other, and Z ^a and Z ^b each have the same meaning as Z ^{a in the} general formula (C) and may be the same or different from each other. A tricyclic compound represented by the formula (1) can be used.

It is effective that these compounds are mixed and used as a Sc liquid crystal composition, but it is sufficient that the composition shows the Sc phase, and it is not always necessary for each compound to show the Sc phase.

By adding the compound of the present invention represented by the general formula (I) and, if necessary, other optically active compound as a chiral dopant to the thus obtained Sc liquid crystal composition, a wide temperature range including room temperature can be obtained. A liquid crystal composition exhibiting the Sc ^* phase can be easily obtained.

The liquid crystal composition obtained by adding the compound of the present invention represented by the general formula (I) to the above Sc matrix liquid crystal composition is a thin film of about 1 to 20 μm between two transparent glass electrodes. By encapsulating as, it can be used as a display cell. In order to obtain good contrast, it is necessary to make the monodomain uniformly oriented. Although this reason is has been attempted many methods, as the liquid crystal material to exhibit good orientation, I phase -N * (chiral nematic) from the high-temperature side phase -S _A (smectic A) phase -Sc * It shows a phase series of phases, and it is said that it is necessary to increase the spiral pitch in the N * phase and the Sc ^* phase.

In order to increase the helical pitch, generally, a method of mixing an appropriate amount of chiral compounds having opposite twist directions is used, but the compound of the present invention requires a small addition amount for high-speed response. However, since the pitch of the helix induced by such an addition is quite large, its adjustment is easy.

[0059]

EXAMPLES The present invention will be specifically described below with reference to examples, but of course the gist and scope of application of the present invention are not limited by these examples.

The structures of the respective compounds are NMR, IR and MS.
Confirmed by. The phase transition temperature was measured by using a polarization microscope equipped with a temperature control stage and a differential scanning calorimeter (DSC) together. In IR, (KBr) represents measurement by tableting, (neat) represents measurement by liquid film, and (Nujol) represents measurement in suspension in liquid paraffin. In NMR, CDCl ₃ represents a solvent, s represents a singlet, d represents a doublet, t represents a triplet, m represents a multiplet, and, for example, dd represents a doublet doublet. Temperature represents ° C and all% in the composition represent% by weight.

Example 1 Synthesis of (2S, 4R) and (2R, 4R) -2- (4-hydroxyphenyl) -2-methyl-4-decanolide

(1-a) Synthesis of (2S, 4R) and (2R, 4R) -2- (4-methoxyphenyl) -2-methyl-4-decanolide

[0063]

[Chemical 15]

To a solution of 1.08 g (6.0 mmol) of 2- (4-methoxyphenyl) propionic acid in 30 ml of tetrahydrofuran (THF) was added 11.8 ml (18.0 mm) of a 1.52 M butyllithium-hexane solution at -78 ° C.
ol) was added and stirred for 1 hour. (R) -1,2-epoxyoctane 898 mg (7.0 mmol) THF1
0 ml solution, hexamethylphosphoric triamide (HMP
A) 10 ml was added, the temperature was raised to room temperature, and the mixture was stirred overnight. Add 20 ml of saturated ammonium chloride and add pH 1 with 3M hydrochloric acid.
After extraction and concentration with 350 ml of ether, 10 mg of p-toluenesulfonic acid and 50 ml of toluene were added, and the mixture was heated with stirring for 2 hours. The solvent was distilled off under reduced pressure and column chromatography (silica gel, hexane / ethyl acetate = 6 /
Separation and purification in 1), non-polar component (2S, 4R) -2-
(4-Methoxyphenyl) -2-methyl-4-decanolide 277 mg (yield 10%), polar component (2R, 4R)
508 mg of 2- (4-methoxyphenyl) -2-methyl-4-decanolide was obtained (yield 29%).

(2R, 4R) -2- (4-Methoxyphenyl) -2-methyl-4-decanolide colorless viscous liquid

[Α] _D + 34.3 ° (c = 1.25, CH
Cl ₃ , 20 ° C)

IR (neat) 2930, 2850,
1760, 1505, 1450, 1250, 1175,
1025,825 cm ^-1

¹ H NMR (CDCl ₃ ) δ 0.88
(T, J = 6.8Hz, 3H), 1.24-1.58
(M, 9H), 1.61 (s, 3H), 1.68-1.7
8 (m, 1H), 2.26 (dd, J = 12.8 and
6.1 Hz, 1 H), 4.52 (ddt, J = 9.1, 7.
4, and 6.1Hz, 1H), 3.80 (s, 3H),
6.88 (d, J = 8.9 Hz, 2H), 7.36 (d,
J = 8.8Hz, 2H)

MS m / z 290 (M ⁺ , 27), 2
46 (11), 231 (23), 162 (15), 16
1 (100), 149 (12), 148 (46), 14
7 (15)

Elemental analysis: Calculated as C ₁₀ H ₂₀ O ₃ : C, 74.45; H, 9.02% Actual value: C, 74.28; H, 9.07%

(2S, 4R) -2- (4-methoxyphenyl) -2-methyl-4-decanolide

Colorless viscous liquid

[Α] _D −44 ° (c = 1.24, CHCl ₃ , 20 ° C.)

IR (neat) 2960, 2890,
1775, 1615, 1520, 1470, 1255
1185, 1035, 835 cm ^-1

¹ H NMR (CDCl ₃ ) δ 0.88
(T, J = 7.1Hz, 3H), 1.21-1.48
(M, 8H), 1.55-1.63 (m, 1H), 1.7
1-1.79 (m, 1H), 1.95 (dd, J = 12.
8 and 10.7 Hz, 1 H), 2.71 (dd, J = 1)
2.8 and 4.9 Hz, 1 H), 3.80 (s, 3
H), 4.20 (d, J = 8.9 Hz, 2H), 6.88
(D, J = 8.9 Hz, 2H), 7.30 (d, J = 8.
9Hz, 2H)

MS m / z 290 (M ⁺ , 20), 2
31 (22), 162 (100), 149 (11), 1
48 (46), 135 (27), 133 (16), 12
1 (14)

Elemental analysis: Calculated as C ₁₈ H ₂₀ O ₃ : C, 74.45; H, 9.02% Actual value: C, 74.34; H, 9.14%

(1-b) (2S, 4R) -2- (4-hydroxyphenyl) -2
-Methyl-4-decanolide synthesis

[0079]

[Chemical 16]

Aluminum chloride 1.5 g (1.8 mmo
l) dimethyl sulfide 1 ml, dichloromethane 20
(2S, 4R) -2- (4-methoxyphenyl) -2-methyl-4-decanolide 527 in a ml solution under ice cooling.
A solution of mg (1.8 mmol) in 5 ml of dichloromethane was added, and the mixture was stirred at 30 ° C. for 2 hours. Neutralize by adding saturated aqueous sodium hydrogen carbonate solution, filter through Celite, ethyl acetate 2
After extraction with 00 ml, wash with saturated aqueous sodium chloride solution,
The extract was dried over anhydrous magnesium sulfate, filtered, and concentrated. The residue is separated and purified by column chromatography (silica gel, hexane / ethyl acetate = 3/1) (2S, 4R) -2.
407 mg (yield 82%) of-(4-hydroxyphenyl) -2-methyl-4-decanolide was obtained.

Colorless viscous liquid

[Α] _D −44.8 ° (c = 1.33, CH
Cl ₃ , 20 ° C)

IR (neat) 3400, 2950,
2880, 1715, 1615, 1600, 1520,
1450, 1380, 1275, 1205, 1180,
1,100,1010,835 cm ^-1

¹ H NMR (CDCl ₃ ) δ 0.87
(T, J = 6.9 Hz, 3H), 1.22-1.48
(M, 8H), 1.54-1.63 (m, 1H), 1.7
1-1.80 (m, 1H), 1.95 (dd, J = 12.
9 and 10.7 Hz, 1H), 2.70 (dd, J = 1)
2.9 and 5.0 Hz, 1H), 4.23 (ddt, J
= 10.7, 7.4, and 5.2 Hz, 1H), 6.81
(D, J = 8.8 Hz, 2H), 7.20 (d, J = 8.
8Hz, 2H)

MS m / z 276 (M ⁺ , 10), 2
32 (10), 217 (13), 148 (12), 14
7 (100), 135 (10), 134 (56), 13
3 (17), 121 (21), 119 (13), 108
(17), 91 (11)

Elemental analysis: Calculated as C ₁₇ H ₂₄ O ₃ : C, 73.88; H, 8.75% Actual value: C, 73.64; H, 8.88%

(1-c) (2R, 4R) -2- (4-hydroxyphenyl) -2
-Methyl-4-decanolide synthesis

[0088]

[Chemical 17]

Instead of (2S, 4R) -2- (4-methoxyphenyl) -2-methyl-4-decanolide, (2
R, 4R) -2- (4-Methoxyphenyl) -2-methyl-4-decanolide was used in the same manner as in (1-b) except that 414 mg (1.4 mmol) was used (2R,
4R) -2- (4-hydroxyphenyl) -2-methyl-4-decanolide 382 mg (yield 98%, optical purity 9
9% ee) was obtained.

Colorless plate crystals

Melting point 87-88 ° C.

[Α] _D + 33.8 ° (c = 0.94, CH
Cl ₃ , 20 ° C)

IR (neat) 3420, 2950,
2930, 2860, 1750, 1515, 1215,
1190, 1060, 925, 810, 650, 595
cm ^-1

¹ H NMR (CDCl ₃ ) δ 0.88
(T, J = 6.9 Hz, 3H), 1.25-1.51
(M, 8H), 1.52-1.63 (m, 1H), 1.6
1 (s, 3H), 1.71-1.80 (m, 1H), 2.
25 (dd, J = 12.8 and 9.3 Hz, 1H),
2.44 (dd, J = 12.8 and 6.1 Hz, 1
H), 4.54 (ddt, J = 9.0, 7.5, and5.
8Hz, 1H), 6.77 (d, J = 8.8Hz, 2
H), 7.29 (d, J = 8.8Hz, 2H)

MS m / z 276 (M ⁺ , 9), 23
2 (10), 217 (12), 148 (13), 135
(11), 133 (17), 121 (21),

Elemental analysis: Calculated as C ₁₇ H ₂₄ O ₃ : C, 73.88; H, 8.75% Actual value: C, 73.80; H, 8.90%

Example 2 Synthesis of (2S, 4R) -2- [4- (4-octylbenzoyloxy) phenyl] -2-methyl-4-decanolide

[0098]

[Chemical 18]

(2S, manufactured in (1-b) of Example 1)
50 mg of 4R) -2- (4-hydroxyphenyl) -2-methyl-4-decanolide and 46 mg of 4-octylbenzoic acid chloride were dissolved in 4 ml of dichloromethane, 1 ml of pyridine was added, and the mixture was stirred for 6 hours under solvent reflux. After cooling, 50 ml of ether and dilute hydrochloric acid were added, the organic layer was separated, washed with water, and dehydrated with anhydrous sodium sulfate. The crude product obtained by distilling off the solvent was purified by column chromatography (silica gel, hexane / ethyl acetate = 5/1) to obtain 61 mg of the title compound as white crystals.

Melting point 69 ° C.

IR (Nujol) 1730, 161
0,1510,1260,1210,1170,106
0,1020,760cm ^-1

¹ H NMR (CDCl ₃ ) δ 0.87
-0.90 (m, 6H), 1.27-2.03 (m, 22
H), 2.65-2.78 (m, 4H), 4.22-4.2
5 (m, 1H), 7.20-8.11 (m, 8H)

Example 3 Synthesis of (2R, 4R) -2- [4- (4-octylbenzoyloxy) phenyl] -2-methyl-4-decanolide

[0104]

[Chemical 19]

(2S, 4R) -used in Example 2
The title compound was obtained by using (2R, 4R) -2- (4-hydroxyphenyl) -2-methyl-4-decanolide instead of 2- (4-hydroxyphenyl) -2-methyl-4-decanolide. Obtained. The phase transition temperatures are shown in Table 1.

Example 4 Synthesis of (2S, 4R) -2- [4- (4-octyloxybenzoyloxy) phenyl] -2-methyl-4-decanolide

[0107]

[Chemical 20]

The title compound was obtained by using 4-octyloxybenzoic acid chloride instead of 4-octylbenzoic acid chloride used in Example 2. The phase transition temperatures are shown in Table 1.

Example 5 Preparation of Sc ^* Composition

A matrix liquid crystal having a Sc phase having the following composition was prepared.

[0111]

[Chemical 21]

The melting point of this host liquid crystal is 12.5 ° C.,
It showed Sc phase up to 55.5 ° C, S _A (smectic A) phase up to 64.5 ° C, and N (nematic) phase up to 70 ° C.

98% of this base liquid crystal and N obtained in Example 4
A liquid crystal composition was prepared by mixing 2% of the compound of O.3 with Sc ^* phase up to 52.5 ° C and S _A up to 65 ° C.
The phase showed an N * phase up to 69 ° C. The melting point was unclear.

(Example 6) Preparation of display device

The Sc ^* composition obtained in Example 5 was heated to form an isotropic liquid. This is filled in a glass cell having a thickness of about 2 μm and subjected to orientation treatment by polyimide-rubbing,
It was gradually cooled to room temperature to obtain an oriented Sc ^* phase monodomain. A rectangular wave with an electric field strength of 10 Vp-p / μm was applied to this cell and its electro-optical response was measured.
As a result, a high-speed response of 186 μsec was confirmed. At this time, the tilt angle is 20.5 ° and the spontaneous polarization is 1.47 nC /
It was cm ² .

[0116]

INDUSTRIAL APPLICABILITY The optically active compound represented by the general formula (I) of the present invention can induce a large spontaneous polarization by adding it as a so-called chiral dopant to another matrix liquid crystal composition, and has a wide temperature range. A liquid crystal composition capable of high-speed response can be provided. Further, the compound of the general formula (I) of the present invention is industrially easily produced, is colorless, and is very excellent in chemical stability against water, light, particularly acids, bases and the like, and is practical. Furthermore, the chiral smectic liquid crystal composition of the present invention can realize a high-speed response on the order of 100 μsec, and is extremely useful as an optical switching element for display.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C07D 407/12 307 8829-4C C09K 19/34 7457-4H G02F 1/13 500 9225-2K (72 ) Inventor Tamijiro Hiyama 4-29-3-101 Kamizuruma, Sagamihara City, Kanagawa Prefecture (72) Inventor Tetsuo Kusumoto 3-16-104 Sakaemachi, Sagamihara City, Kanagawa Prefecture (72) Akiko Nakayama 1380, Yamazaki Town, Machida City, Tokyo -K-702

Claims (14)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R ¹ represents a fluorine atom, a chlorine atom, a cyano group or an alkyl group having 1 to 18 carbon atoms which may be substituted with an alkoxyl group having 1 to 10 carbon atoms,
X is a single bond, -O-, -S-, -CO-, -COO-,
Represents -OCO-, -OCOO-, wherein ring A and ring B are each independently a 1,4-phenylene group optionally substituted by 1 or 2 fluorine atoms, trans-
1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,
5-diyl group, a 3,6-diyl or 1,3-dioxane-2,5-diyl group, Y -COO -, - OCO -, - CH 2 O -, - OCH 2 -,
Represents —CH ₂ CH ₂ —, —C≡C—, or a single bond,
m represents 0 or 1, n represents 1 or 2, Z
Represents —COO—, or —CH ₂ O—, R ² represents a linear or branched alkyl group having 1 to 18 carbon atoms, and the asymmetric carbon atoms at the 2-position and 4-position of the lactone ring are Each is independently in the (R) or (S) configuration. ) An optically active lactone derivative represented by: 2. The optically active lactone derivative according to claim 1, wherein n = 1. 3. The optically active lactone derivative according to claim 2, wherein m = 0. 4. The optically active lactone derivative according to claim 3, wherein Z is —COO—. 5. Ring A is 1,4-phenylene group or 1,
The optically active lactone derivative according to claim 4, which is a 4-cyclohexylene group. 6. The method according to claim 5, wherein X is a single bond or —O—.
The optically active lactone derivative described. 7. The optically active lactone derivative according to claim 6, wherein R ¹ is an alkyl group having 2 to 12 carbon atoms. 8. The optically active lactone derivative according to claim 7, wherein R ² is a linear alkyl group having 1 to 10 carbon atoms. 9. X is —O— and ring A is 1,4-
The optically active lactone derivative according to claim 8, which is a phenylene group. 10. A compound represented by the general formula (II): (In the formula, n represents 1 or 2, and R ² has 1 carbon atom.
To 18 linear or branched alkyl groups, the asymmetric carbon atoms at the 2- and 4-positions of the lactone ring are each independently in the (R) or (S) configuration. ) An optically active lactone derivative represented by: 11. The optically active lactone derivative according to claim 10, wherein n = 1. 12. A liquid crystal composition containing the optically active lactone derivative according to claim 1. 13. The liquid crystal composition according to claim 12, which exhibits a ferroelectric chiral smectic phase. 14. A liquid crystal display device using the liquid crystal composition according to claim 12 or 13.