JPH06100551A - Optically active 2,5-substituted tetrahydrofuran derivative, its production and liquid crystal composition and liquid crystal display element containing the derivative - Google Patents

Abstract

PURPOSE:To provide a new compound useful as a ferroelectric liquid crystal display material especially having excellent quick response and memory property. CONSTITUTION:The compound of formula I (R<1> is 1-18C alkyl; X is single bond, O, COO, OCO or OCOO; rings A and B are 1,4-phenylene, trans-1,4-cyclohexylene, pyridine-2,5-diyl, etc.; R<2> is 1-18C alkyl), e.g. (5R)-5-hexyl-2-[4-(4-octyloxyphenyl) phenylmethyloxy]tetrahydrofuran. The compound of formula I can be produced by condensing an optically active lactol derivative of formula II to an alcohol derivative of formula III in the presence of an acid (e.g. anhydrous hydrogen chloride) and separating the produced diastereomer by a conventional method. A liquid crystal composition having large spontaneous polarity and exhibiting quick response over a wide temperature range can be produced by adding a small amount of the compound of formula I as a chiral dopant to a mother crystal.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel optically active
The present invention relates to a 5-substituted tetrahydrofuran derivative and a liquid crystal material containing the derivative, and particularly to a ferroelectric liquid crystal display material excellent in high-speed response and memory property.

[0002]

2. Description of the Related Art Liquid crystal display devices are widely used at present due to their excellent features (low voltage driving, low power consumption, thin display, and can be used in bright places without eye strain). However, among them, the twisted nematic (TN) type, which is the most general display type, has a very slow response as compared with other light emitting type display types such as CRT, and stores the display when the applied electric field is cut off ( Since there is no memory effect), there are many restrictions on application to moving screens such as optical shutters that require high-speed response, printer heads, or even TVs that require time-division driving, and it is not always a suitable display method. I couldn't say it.

Recently, a display method using a ferroelectric liquid crystal has been reported.
Since a high-speed response of 1000 times and a memory effect can be obtained, it is expected as a next-generation liquid crystal display element, and research and development are being actively conducted at present.

The liquid crystal phase of the ferroelectric liquid crystal belongs to the tilt type chiral smectic phase, and the chiral smectic C (hereinafter abbreviated as SC ^* ) phase is the most preferable because it has the lowest viscosity. A large number of liquid crystal compounds exhibiting the SC ^* phase (hereinafter abbreviated as SC ^* compounds) have already been synthesized and studied, but in order to be used as a ferroelectric liquid crystal device, the following conditions must be satisfied. .
That is, (a) the SC ^* phase is exhibited in a wide temperature range including room temperature, and (b) the SC ^* phase has an appropriate phase series on the high temperature side in order to obtain good orientation, and the helical pitch is Large, (c) having an appropriate tilt angle, (d) small viscosity, (e) large spontaneous polarization to some extent,
(F) It is necessary to satisfy the conditions such as showing a fast response. However, a compound that alone satisfies these conditions is not known. Therefore, it is necessary to mix several or more kinds of compounds and use them as a liquid crystal composition showing an SC ^* phase (hereinafter abbreviated as SC ^* liquid crystal composition).

As a method for preparing an SC ^* liquid crystal composition, a dopant comprising an optically active compound is added as a so-called chiral dopant to a host liquid crystal exhibiting a smectic C (hereinafter abbreviated as SC) phase comprising an achiral compound. Can obtain a composition of lower viscosity,
This is the most common because it enables a fast response. Here, the compound used as the chiral dopant does not necessarily have to exhibit the SC ^* phase or even the liquid crystal phase by itself, but a small amount of the compound may induce sufficient spontaneous polarization in the liquid crystal composition, and It is necessary to exhibit properties such that the pitch of the helix induced as a chiral dopant is sufficiently large.

In order to induce a large spontaneous polarization in a liquid crystal composition as a chiral dopant, a group having a strong dipole moment must be fixed as close as possible to the central skeleton (core) and asymmetric carbon of the compound molecule. Is already known to be necessary. On the basis of such an idea, the present inventors have made general formula (IV)

[0007]

[Chemical 6]

An optically active lactone derivative represented by the formula (wherein Mes represents a liquid crystal skeleton and R represents an alkyl group) was synthesized. Furthermore, this compound can induce a sufficiently large spontaneous polarization even if added in a small amount, so that S with a high response can be obtained.
It has been found that a C ^* liquid crystal composition can be prepared.
(Proceedings of 16th Liquid Crystal Conference, page 44,
(-286673)

[0009]

However, in the compound represented by the general formula (IV), although the carbonyl group of the lactone ring gives a large dipole moment to the compound itself, at the same time, the viscosity of the compound is extremely low. There was a problem of making it big. Therefore, a larger amount of spontaneous polarization is induced by adding a small amount to the host liquid crystal, but at the same time, the viscosity of the composition is also increased, which is not always sufficient in terms of high-speed response.

The problem to be solved by the present invention is to provide an optically active compound and a synthetic intermediate which can induce a large spontaneous polarization by adding a small amount as a chiral dopant to a host liquid crystal and enable a high speed response. It is intended to provide a ferroelectric liquid crystal display material containing an optically active compound.

[0011]

In order to solve the above-mentioned problems, the present invention has the general formula (I)

[0012]

[Chemical 7]

(In the formula, R ¹ represents an optionally substituted alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 2 to 14 carbon atoms, and X represents a single bond. , -O-, -COO-, -OCO-, or -OCOO
Represents-, preferably represents -O- or a single bond,
Ring A and ring B are each independently a 1,4-phenylene group optionally substituted by one or two fluorine atoms, a trans-1,4-cyclohexylene group, a pyridine-2,5-diyl group. A group, a pyrimidine-2,5-diyl group,
Represents a pyrazine-2,5-diyl group, a pyridazine-3,6-diyl group or a 1,3-dioxane-2,5-diyl group, at least one of which is substituted with 1 or 2 fluorine atoms. Represents a 1,4-phenylene group, preferably ring A and ring B each represent a 1,4-phenylene group optionally substituted by one or two fluorine atoms, and particularly preferably ring A and ring Both B's represent a 1,4-phenylene group, R ² represents an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, which is at the 2-position or 5-position of the tetrahydrofuran ring. Each asymmetric carbon atom is independently in the (R) or (S) configuration. ), Which is an optically active 2,5-substituted tetrahydrofuran derivative.

The present invention also provides a compound represented by the general formula (II) as a synthetic intermediate for the compound represented by the general formula (I).

[0015]

[Chemical 8]

(Wherein R ² has the same meaning as in formula (I), and the asymmetric carbon atom at the 5-position of the tetrahydrofuran ring is in the (R) or (S) configuration). Derivatives are provided.

The present invention further provides a method for producing the optically active tetrahydrofuran derivative represented by the general formula (I).

The compound represented by formula (I) according to the present invention can be produced by the following production method. That is, the optically active lactol derivative represented by the general formula (II) and the general formula (III)

[0019]

[Chemical 9]

(Wherein R ¹ , X, ring A and ring B have the same meanings as in the general formula (I)) and condensed with an alcohol derivative in the presence of an acid such as anhydrous hydrogen chloride. Then, it can be easily produced by separating the obtained diastereomer using a conventional separation method.

The optically active lactol derivative represented by the general formula (II) is a novel compound and can be produced, for example, as follows. That is, the general formula (V)

[0022]

[Chemical 10]

(Wherein R ² has the same meaning as in the general formula (I)) and the optically active oxirane derivative is reacted with the dianion of acetic acid to give the general formula (VI).

[0024]

[Chemical 11]

(In the formula, R ² has the same meaning as in formula (I), and the asymmetric carbon atom at the 5-position of the lactone ring is
(R) or (S) arrangement. ) To obtain an optically active lactone derivative.

The optically active lactone derivative is reduced with diisopropylaluminum hydride to obtain an optically active lactol derivative represented by the general formula (II).

Many of the compounds represented by the general formula (III) are already known, but if necessary, they can be easily obtained by reducing the corresponding carboxylic acid or aldehyde.

As described above, the general formula (I) of the present invention is used.
The compounds represented by can be obtained, and the individual specific compounds belonging to these compounds have a phase transition temperature such as a melting point,
It can be confirmed by means of elemental analysis, infrared absorption spectrum (IR), nuclear magnetic resonance spectrum (NMR), mass spectrum (MS) and the like.

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

[0030]

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

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

The liquid crystal composition of the present invention has the above general formula (I).
The compound contains at least one compound represented by the formula (1) as a constituent. In particular, as a ferroelectric liquid crystal display material, a matrix liquid crystal showing an SC phase as a main component (hereinafter referred to as SC
^* Abbreviated as host liquid crystal. In the above, a SC ^* liquid crystal composition containing at least one compound represented by the general formula (I) as a part or all of the chiral dopant 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, it is possible to prevent a so-called reverse domain as a TN type liquid crystal or S
It can be used for applications such as TN liquid crystal.

One of the excellent features of the compound represented by the general formula (I) is that, when used as a chiral dopant for a ferroelectric liquid crystal, the optically active lactone derivative represented by the above general formula (VI). However, it is possible to induce a considerably large spontaneous polarization. For example, as shown in Example 4 which will be described later, in the SC ^* liquid crystal composition comprising 20% by weight of the compound No. 2 in Table 1 and 80% by weight of the SC phase host liquid crystal, the spontaneous emission at 25 ° C. The polarization value is 2.09 nC / cm ² , which is most commonly used as a chiral source in liquid crystals (S).
SC ^* compounds derived from 2-methylbutanol, for example:
It can be seen that the spontaneous polarization of 4-[(S) -2-methylbutoxy] phenyl 4-decyloxybenzoate is substantially higher than that of the same level when measured alone without addition to the host liquid crystal. Therefore, if about 10% 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.

The compound represented by the general formula (I) is
For example, as compared with the optically active lactone derivative represented by the general formula (VI), its viscosity is small because there is no carbonyl group. Therefore, the SC ^* liquid crystal composition using the compound represented by the general formula (I) is capable of high-speed response for its spontaneous polarization.

The compound represented by the general formula (I) does not show not only the SC ^* phase but also the liquid crystal phase by itself, but when added in a small amount, the temperature range of the SC ^* phase of the liquid crystal composition and other liquid crystal phases is not so large. Since it is not narrowed, it is easy to obtain a ferroelectric liquid crystal composition exhibiting the SC ^* phase in a wide temperature range.

S used in the host liquid crystal to be added with the compound represented by the general formula (I) of the present invention as a dopant
Examples of the liquid crystal compound showing the C phase (hereinafter, abbreviated as SC compound) include, for example, the following general formula (A).

[0037]

[Chemical 12]

(In the formula, R ^a and R ^b represent an 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). Phenylbenzoate compounds represented by the general formula (B)

[0039]

[Chemical 13]

A phenylpyrimidine compound represented by the formula (wherein R ^a and R ^b have the same meaning as in the general formula (A)) can be given. In addition, the general formula (C) including the general formula (A) and the general formula (B)

[0041]

[Chemical 14]

(In the formula, R ^a and R ^b have the same meanings as in the general formula (A), and the ring L and the ring M are 1, 4 respectively.
-Phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, pyridazine-3,6
Represents a -diyl group, a 1,3-dioxane-2,5-diyl group or a halogen-substituted product thereof, which may be the same or different from each other, 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)

[0044]

[Chemical 15]

(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). And these may be the same or different from each other, Z ^a and Z ^b each have the same meaning as Z ^{a in the} general formula (C), and these may be the same or different from each other. It is possible to use a tricyclic compound represented by

It is effective that these compounds are mixed and used as an SC host liquid crystal, but it is sufficient that the composition shows the SC phase, and the individual compounds do not necessarily have to show the SC phase.

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

The present invention also provides a liquid crystal display device having a liquid crystal composition containing the optically active tetrahydrofuran derivative represented by the general formula (I) as a constituent element.

The SC ^* liquid crystal composition obtained by adding the compound represented by the general formula (I) of the present invention to the above SC host liquid crystal is formed as a thin film of about 1 to 20 μm between two transparent glass electrodes. By enclosing it, it can be used as a display cell. In order to obtain good contrast, it is necessary to make the monodomain uniformly oriented. For this reason, many methods have been tried, but in order to exhibit good alignment properties, the liquid crystal material should be selected from the I phase-N ^* (chiral nematic) phase-SA (smectic A) phase-SC ^* phase from the high temperature side. 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 spiral pitch, generally, a method of mixing an appropriate amount of chiral compounds having mutually opposite twist directions is used, but in the compound represented by the general formula (I) of the present invention, the induced spiral pitch is Because it is reasonably large, its adjustment is easy.

[0050]

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

The structures of the compounds are elemental analysis, NMR,
Confirmed by IR and MS. The phase transition temperature was measured by using a polarization microscope equipped with a temperature control stage and a differential scanning calorimeter (DSC) together. (KBr) in IR
Represents the measurement by tableting, and (neat) represents the measurement by the liquid film. 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. J represents a coupling constant. M ^{+ in} MS
Represents the parent peak, and the numerical value in parentheses represents the relative intensity of the peak. All "%" in the liquid crystal composition represents "% by weight".

Example 1 (5R) -5-hexyl-
2-hydroxytetrahydrofuran (general formula (II)
Compound represented by (1) Synthesis of (1-a) (R) -4-decanolide

[0053]

[Chemical 16]

15.4 ml of diisopropylamine (110
(100 mmol) of tetrahydrofuran (THF) in 100 ml of solution was added with 71.0 ml (110 mmol) of 1.5 M butyllithium-hexane solution at -78 ° C, and the mixture was stirred for 30 minutes. Subsequently, acetic acid 3.0 g (50 mmol) THF5
Add 0 ml solution and stir for 1 hour, then add (R) -1,2-
Epoxy octane 6.4 g (50.0 mmol) TH
F50 ml solution was added and the temperature was raised to room temperature. After the reaction,
3M hydrochloric acid was added until the pH of the reaction solution became 1, the reaction product was extracted three times with 100 ml of ethyl acetate, the extract was concentrated, and 200 ml of toluene and 50 mg of p-toluenesulfonic acid were added to the obtained residue. The mixture was heated to reflux for 2 hours. After the reaction solution was concentrated, the obtained residue was distilled under reduced pressure to obtain (R)
1.23 g (yield 14%) of -4-decanolide was obtained.

Colorless oily substance Boiling point 160 ° C./0.2 mmHg IR (neat) 2940,2870,1780,1180 cm ^{−1 1} H NMR (CDCl ₃ ) δ 0.89 (t, J =
6.8Hz, 3H), 1.25-1.52 (m, 8H),
1.55-1.64 (m, 1H), 1.70-1.79
(M, 1H), 1.85 (dtd, J = 12.7, 9.
5, and 8.0 Hz, 1H), 2.28-2.36
(M, 1H), 2.51-2.55 (m, 2H), 4.
45-4.52 (m, 1H) MS m / z 171 (M ⁺⁺ 1, 0.4), 85 (1
00), 56 (12)

(1-b) (5R) -5-hexyl-2
-Synthesis of hydroxytetrahydrofuran

[0057]

[Chemical 17]

(R) -4-obtained in Example (1-a)
To a solution of 575 mg (3.4 mmol) of decanolide in 5 ml of dichloromethane was added 4.1 ml (4.1 mmol) of a 1.0 M diisobutylaluminum hydride-toluene solution at -78 ° C, and the mixture was stirred for 2 hours. After the reaction, 3M hydrochloric acid 5
After adding ml, and filtering through Celite, the reaction product was extracted 3 times with 50 ml of ethyl acetate, separated and purified by column chromatography (silica gel, toluene / ether = 5/1), and (5R) -5 Hexyl-2-hydroxytetrahydrofuran (525 mg, yield 90%) was obtained.

Colorless oily substance IR (neat) 3430, 2930, 2860, 1
460,1010 cm ^{-1 1} H NMR (CDCl ₃ ) δ 0.88 (t, J =
6.7 Hz, 3 H), 1.25 to 1.61 (m, 10
H), 1.65-1.77 (m, 1H), 1.80-
2.00 (m, 2H), 2.01 to 2.16 (m, 1
H), 2.86 (s, 0.4H), 2.92 (s, 0.
6H), 3.94-4.01 (m, 0.4H), 4.1
6-4.23 (m, 0.6H), 5.56 (t, J =
3.4 Hz, 0.4 H), 5.53-5.56 (m, 0.
6H) MS m / z 171 (M ⁺ -1,1), 155 (6
2), 137 (11), 97 (14), 88 (10
0), 82 (19)

Example 2 (5R) -5-hexyl-
Synthesis of 2- [4- (4-octyloxyphenyl) phenylmethyloxy] tetrahydrofuran (compound represented by general formula (I))

[0061]

[Chemical 18]

(5R) -5 obtained in Example (1-b)
-Hexyl-2-hydroxytetrahydrofuran 120
mg (0.70 mmol), 4-hydroxymethyl-4 '
A solution of 261 mg (0.84 mmol) octyloxybiphenyl in 5 ml dichloromethane was bubbled with dry hydrogen chloride at 0 ° C. and left overnight at −20 ° C. The reaction mixture was concentrated under reduced pressure, and the obtained residue was subjected to column chromatography (silica gel, hexane / ethyl acetate = 20 /
Separation and purification using (1), (5R) -5-hexyl-
2- [4- (4-octyloxyphenyl) phenylmethyloxy] tetrahydrofuran Non-polar component (Compound No. 1 in Table 1) 107 mg (yield 34%), and polar component (No. in Table 1) .2 compound) 83 mg (yield 26
%) Was obtained.

Non-polar component Colorless crystal Melting point 63 ° C. [α] _D + 44 ° (c = 1.11, CHCl ₃ , 20
° C) IR (KBr) 2940, 1860, 1610, 15
00,1250,1050,810 cm ^{-1 1} H NMR (CDCl ₃ ) δ 0.889 (t, J
= 6.1 Hz, 3 H), 0.891 (t, J = 5.7 Hz,
3H), 1.25-1.52 (m, 20H), 1.58
-1.66 (m, 1H), 1.76-1.83 (m, 2
H), 1.89-1.97 (m, 1H), 2.02-
2.14 (m, 2H), 3.99 (t, J = 6.6Hz,
2H), 4.07-4.13 (m, 1H), 4.50
(D, J = 11.8 Hz, 1H), 4.75 (d, J = 1
1.8 Hz, 1 H), 5.25 (dd.J = 5.0 and
1.6Hz, 1H), 6.95 (d, J = 8.8Hz, 2
H), 7.38 (d, J = 8.3 Hz, 2H), 7.49
(D, J = 8.8 Hz, 2H), 7.51 (d, J = 8.
3 Hz, 2H) MS m / z 466 (M ⁺ , 29), 313 (1
0), 312 (40), 295 (20), 200 (6
9), 199 (17), 184 (22), 183 (4
8), 153 (15), 95 (17), 81 (19),
69 (30), 41 (100) Calculated elemental analysis _{C 31 H 46 O 3: C} , 79.78; H, 9.94% Found: C, 79.51; H, 10.10 %

Polar component Colorless crystal Melting point 32 ° C. [α] _D −16 ° (c = 0.82, CHCl ₃ , 20
° C) IR (KBr) 2950, 1610, 1510, 14
70,1250,1040,810 cm ^{−1 1} H NMR (CDCl ₃ ) δ 0.88 (t, J =
7.0 Hz, 3 H), 0.89 (t, J = 6.8 Hz, 3
H), 1.24-1.52 (m, 19H), 1.67-
1.83 (m, 4H), 1.87-1.07 (m, 3
H), 4.00 (t, J = 6.6 Hz, 2H), 4.04
-4.11 (m, 1H), 4.47 (d, J = 11.7)
Hz, 1H), 4.76 (d, J = 11.7Hz, 1H),
5.17 (d, J = 4.6Hz, 1H), 6.95 (d,
J = 8.8Hz, 2H), 7.38 (d, J = 8.3Hz,
2H), 7.50 (d, J = 8.8Hz, 2H), 7.5
2 (d, J = 8.3 Hz, 2H) MS m / z 466 (M ⁺ , 29), 313 (1
0), 312 (40), 295 (20), 200 (6
9), 199 (17), 184 (22), 183 (4
8), 153 (15), 95 (17), 81 (19),
69 (30), 41 (100) Calculated elemental analysis _{C 31 H 46 O 3: C} , 79.78; H, 9.94% Found: C, 79.63; H, 10.16 %

Example 3 Preparation of SC ^* Liquid Crystal Composition An SC host liquid crystal (H-1) having the following composition was prepared.

[0066]

[Chemical 19]

The phase transition temperature of this host liquid crystal was as follows. 12.5 ° C (Cr → SC), 55.5 ° C (SC-SA
), 64.5 ° C (SA-N), 70 ° C (NI). 90% of this SC base liquid crystal (H-1) and No. 1 in Table 1 obtained in Example 2. An SC ^* liquid crystal composition (M-1) consisting of 10% of the compound of 1 was prepared. The phase transition temperature was as follows. 47 ° C (SC ^* -SA), 59 ° C (SA-N ^* ), 6
3.5 ° C (N ^* -I). The melting point was not clear.

Similarly, SC matrix liquid crystal (H-1) 80
% And No. in Table 1. SC ^* consisting of 20% of one compound
A liquid crystal composition (M-2) was prepared. The phase transition temperature was as follows. 46 ° C (SC ^* -SA), 58.5 ° C (SA-N ^* ),
63 ° C (N ^* -I).

Similarly, SC matrix liquid crystal (H-1) 90
% And 1 No. in Table 1 obtained in Example 2. A SC ^* liquid crystal composition (M-3) consisting of 10% of the compound of 2 was prepared. The phase transition temperature was as follows. 43 ° C (SC ^* -SA), 55.5 ° C (SA-N ^* ),
61 ° C (N ^* -I).

Similarly, SC matrix liquid crystal (H-1) 80
% And No. in Table 1 obtained in Example 2. Compound 2 of 2
An SC ^* liquid crystal composition (M-4) consisting of 0% was prepared.
The phase transition temperature was as follows. 31 ° C (SC ^* -SA), 50.5 ° C (SA-N ^* ),
57 ° C (N ^* -I).

Example 4 Preparation of Liquid Crystal Display Device The SC ^* liquid crystal composition (M-2) obtained in Example 3 was heated to the isotropic liquid (I) phase, and this was 2 μm thick. A glass cell made of a transparent electrode plate (polyimide coating-aligned by rubbing) was filled to prepare a display element. When this was gradually cooled to room temperature, a uniformly aligned SC ^* phase liquid crystal display device was obtained.

Electric field strength of 10 V _pp / μm, 5
When a rectangular wave of 0 Hz was applied and the electro-optical response speed was measured, a high-speed response of 186 μsec at 25 ° C. could be confirmed. The tilt angle at this time was 15.5 °, and the contrast was good. Also, this spontaneous polarization is -2.
It was 09 nC / cm ² .

Similarly, the SC ^* liquid crystal composition (M-
Liquid crystal display devices were prepared using 1), (M-3) and (M-4), and their characteristics were measured. The results are shown in Table 2.

[0074]

[Table 2]

[0075]

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 chiral dopant to another host liquid crystal, and has a fast response in a wide temperature range. A liquid crystal composition capable of achieving the above can be provided. In addition, the compound represented by the general formula (I) of the present invention can be easily produced industrially, is colorless, and has excellent chemical stability against water, light, particularly acids, bases, etc. Is. Furthermore, the chiral smectic liquid crystal composition of the present invention can realize a high-speed response of about 100 μsec, and is extremely useful as an optical switching element for display.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal 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 1-9-2-102 Minamidai, Sagamihara City, Kanagawa Prefecture (72) Inventor Kenichi Sato Kamimizo City, Sagamihara City, Kanagawa Prefecture 35-11 (72) Inventor Akiko Nakayama 1380 Yamazaki-cho, Machida-shi, Tokyo K-702

Claims (10)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R ¹ has 1 carbon atom which may have a substituent.
~ 18 alkyl group, X is a single bond, -O-,-
Represents COO-, -OCO-, or -OCOO-, and ring A and ring B are each independently a 1,4-phenylene group optionally substituted by one or two fluorine atoms, 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, at least one Represents a 1,4-phenylene group optionally substituted by 1 or 2 fluorine atoms,
R ² represents an alkyl group having 1 to 18 carbon atoms, and the asymmetric carbon atoms at the 2-position and 5-position of the tetrahydrofuran ring are each independently in the (R) or (S) configuration. ) An optically active 2,5-substituted tetrahydrofuran derivative represented by 2. The optically active tetrahydrofuran derivative according to claim 1, wherein ring A and ring B are 1,4-phenylene groups. 3. The optically active tetrahydrofuran derivative according to claim 2, wherein X is —O—. 4. The optically active tetrahydrofuran derivative according to claim 3, wherein R ¹ is an alkyl group having 2 to 14 carbon atoms. 5. The optically active tetrahydrofuran derivative according to claim 4, wherein R ² is an alkyl group having 1 to 10 carbon atoms. 6. A compound represented by the general formula (II): (In the formula, R ² represents an alkyl group having 1 to 18 carbon atoms, and the asymmetric carbon atom at the 5-position of the tetrahydrofuran ring is
(R) or (S) arrangement. ) An optically active lactol derivative represented by: 7. A compound represented by the general formula (II): (In the formula, R ² represents an alkyl group having 1 to 18 carbon atoms, and the asymmetric carbon atom at the 5-position of the tetrahydrofuran ring is
(R) or (S) arrangement. ) And an optically active lactol derivative represented by the general formula (III): (In the formula, R ¹ has 1 carbon atom which may have a substituent.
~ 18 alkyl group, X is a single bond, -O-,-
Represents COO-, -OCO-, or -OCOO-, wherein ring A and ring B are each independently a 1,4-phenylene group optionally substituted by one or two fluorine atoms, 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, at least one Represents a 1,4-phenylene group optionally substituted by one or two fluorine atoms. ) Is condensed with an alcohol derivative represented by the formula (1) in the presence of an acid, and then the obtained diastereomer is separated to give a compound of the general formula (I) (In the formula, R ¹ has 1 carbon atom which may have a substituent.
~ 18 alkyl group, X is a single bond, -O-,-
Represents COO-, -OCO-, or -OCOO-, wherein ring A and ring B are each independently a 1,4-phenylene group optionally substituted by one or two fluorine atoms, 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, at least one Represents a 1,4-phenylene group optionally substituted by 1 or 2 fluorine atoms,
R ² represents an alkyl group having 1 to 18 carbon atoms, and the asymmetric carbon atoms at the 2-position and 5-position of the tetrahydrofuran ring are each independently in the (R) or (S) configuration. ) A method for producing an optically active 2,5-substituted tetrahydrofuran derivative represented by 8. A liquid crystal composition containing the optically active 2,5-substituted tetrahydrofuran derivative according to claim 1. 9. The liquid crystal composition according to claim 8, which exhibits a ferroelectric chiral smectic phase. 10. A liquid crystal display device using the liquid crystal composition according to claim 8.