JP2974824B2 - Optically active compound, synthetic intermediate thereof, and ferroelectric liquid crystal composition containing the same - Google Patents

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 compound having a .delta.-valerolactone ring in the molecular structure, an intermediate thereof, and a ferroelectric liquid crystal composition containing the same.

[0002]

2. Description of the Related Art At present, liquid crystal widely used as a display material belongs to a nematic phase, and has characteristics such as a light-receiving type that does not cause eyestrain and extremely low power consumption. However, it has the drawbacks that the display is slow and the display becomes invisible depending on the viewing angle.

A display device using a ferroelectric liquid crystal as a device having characteristics of a nematic type liquid crystal that does not cause eyestrain and extremely low power consumption, and having a high-speed response and a high contrast comparable to a light emitting type display device. Printer heads are being considered.

The existence of a ferroelectric liquid crystal was first announced by RB Meyer et al. In 1975 (J. Physique 36, L-69 (1975)), and a chiral smectic C phase (hereinafter, Sm ^* C phase) And a typical example thereof is p-decyloxybenzylidene-p'-amino-2-methylbutylcinnamate (hereinafter abbreviated as DOBAMBC) represented by the following formula.

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[0005]

However, the above-mentioned DOBA
Many of MBC and some of the ferroelectric liquid crystal materials proposed thereafter have a narrow temperature range exhibiting ferroelectricity (the temperature range in which the Sm ^* C phase exists), and are difficult to use alone in practice. . Therefore, in general, various kinds of ferroelectric liquid crystals are mixed to extend the temperature range showing the Sm ^* C phase to a low temperature side and a high temperature side around room temperature. Further, for a printer head that requires an ultra-high-speed response, a ferroelectric liquid crystal having a larger spontaneous polarization than a conventionally developed ferroelectric liquid crystal is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optically active substance which is chemically stable, has no coloration, has excellent light stability, and exhibits a large spontaneous polarization when incorporated into a liquid crystal composition. And to provide a liquid crystal composition comprising:

[0007]

That is, the gist of the present invention is to provide an optically active substance having a δ-valerolactone ring represented by the formula (1), an intermediate thereof, and a liquid crystal composition containing one or more kinds thereof. is there.

[0008]

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(Wherein R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, and 1 to 1 carbon atoms in the alkoxy moiety)
3 is a straight-chain or branched-chain alkoxyalkyl group having 1 to 18 carbon atoms in the alkyl part, or one in which one or more of the hydrogen atoms is halogen-substituted, and has an optically active group. In the case of having a structure which can be an optically active group or a racemic form, R ₂ is an alkyl group having 1 to 18 carbon atoms ,
X is a single bond, -O -, - COO- or -OCO- indicates, Y is a single bond, -OCO- or -OCH ₂ - indicates,
A is

[0010]

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[0011] indicates, B, B 'and B "each represent hydrogen, halogen, a cyano group, a methyl group, a methoxy group or a trihalomethyl group, V is a single bond, -CH ₂ O -, - OCH
₂ -, - COO- or -OCO- indicates, * indicates that the carbon to which it is applied is an asymmetric carbon. )

In the optically active substance of the present invention, R ₁ in Chemical formula ₁ represents a straight-chain or branched-chain alkyl group having 4 to 14 carbon atoms, a straight-chain or branched-chain alkenyl group having 4 to 14 carbon atoms, A linear or branched alkoxyalkyl group having 4 to 14 carbon atoms can be exemplified as a preferable example,
Examples of such a linear alkyl group include n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-butyl
- such as tetradecyl can be exemplified, and as the branched chain alkyl group _{- (CH 2) a C (} CH 3) H (CH 2) b CH 3 (a is an integer of 0, b is 1 to 11 integer And 1
≦ a + b ≦ 11. )). In the case of such a methyl-branched alkyl group, both those having optical activity and those having a racemic form can be suitably used.

Examples of those substituted with halogen by a linear alkyl group include-(CH ₂ ) _k C (W) H (CH ₂ ) _i CH ₃ (where W represents a fluorine, chlorine or bromine atom, and And i are each an integer of 0 to 12 and 2 ≦ k + i ≦ 12), and these are more preferably optically active groups.

[0014] Examples of those substituted with halogen by a branched alkyl group include an alkyl group having a trifluoromethyl branch, which is also preferably an optically active group. _{- (CH 2) a C (} CF 3) H (CH 2) b CH 3 (a, b represents the above-mentioned meanings.)

[0015] As an alkoxyalkyl group of straight chain _{- (CH 2) c OC j} H 2j + 1 Examples of the alkoxyalkyl group branched _{- (CH 2) k C (} CH 3) H (CH 2) j OC j _{H 2j + 1 - (CH 2} ) k C (OC j H 2j + 1) H (CH 2) i CH 3 (j is an integer of 1 to 3, c is an integer of 4 to 14, k, i is the above-mentioned In the case of a branched-chain alkoxyalkyl group, it may be a racemic mixture or an optically active group. As A

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Embedded image Can be exemplified as preferable ones.

From the viewpoint of increasing the response speed of the liquid crystalline composition containing the optically active substance of the present invention, it is preferable to increase the dipole moment around the asymmetric carbon or to increase the rotation hindrance. , of 1 single bond as in Y, -OCO- or -OCH ₂ - is preferably, linearity of the molecule, from the viewpoint of Deeki of inclined liquid crystal phase by the induced dipole moment -OCH ₂ -Is preferable, and from the viewpoint of easiness of synthesis, a single bond,-
Is preferably - OCO- or -OCH _2.

X is preferably a single bond, -O-, -COO- or -OCO- from the viewpoint of ease of synthesis, and V is a single bond from the viewpoints of viscosity and the magnitude of dipole moment. since a bond, -COO from the viewpoint of ease of synthesis -, - OCO -, - OCH 2 - or is preferably -CH ₂ O-in which. R ₂ has a carbon number of 1 to 3 so as not to increase viscosity and not to lower liquid crystallinity.
However, in order to increase the asymmetric effect which is a factor of increasing the spontaneous polarization, the number of carbon atoms is preferably 4 to 12 carbon atoms.
It is preferred that

However, what greatly affects the spontaneous polarization is the effect of fixing the ring. From the viewpoint of the effect of fixing the ring, if the number of carbon atoms is 1 or more, that is, the first methylene group directly bonded to the ring. Is the largest factor that regulates the steric nature of the ring because it is present on both the axial and equatorial sides, so that the effect of the ring regulation of an alkyl group having 1 or more carbon atoms can be evaluated equally, and an alkyl group having 1 to 12 carbon atoms. Is also expected to increase spontaneous polarization, and as mentioned earlier, by increasing the asymmetric effect,
It is considered that a compound having an alkyl group having 4 to 12 carbon atoms further increases spontaneous polarization.

In particular, as the compound having a large spontaneous polarization, the following compounds can be exemplified among the compounds shown in Chemical formula 1. That is, in the formula 1, R ₁ is C _n H _{2n + 1} -or C
_n H _{2n + 1} O- (n = 8 to 12 ), and R ₂ is C _n H _{2n + 1}
− (N = 4 to 12),

Embedded image Y is -OCH ₂ - is compounds showing.

The compound of formula 1 can be produced by the following method. In the case of - Y is -OCH ₂

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A) When R ₂ is a methyl, ethyl or propyl group

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[0022]

When Y is -OCO-

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When X is a single bond (The case where A is p-phenylene is shown as an example)

A) When X is -O- or -COO-

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B) When X is -OCO-

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C) When X is a single bond

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In the above-mentioned production method, when the yield in the reaction using LDA is poor, the use of lithium hexamethyldisilazide or potassium hexamethyldisilazide instead of LDA improves the yield.

The one which is considered to contribute most to the development of spontaneous polarization or potential spontaneous polarization in a ferroelectric liquid crystal or a compound as a compounding material for the ferroelectric liquid crystal is the vicinity of asymmetric carbon. Is considered to be a regulated large permanent dipole moment.

The optically active compound represented by Chemical formula 1 of the present invention has a δ
A valerolactone ring, which has an asymmetric carbon fixed thereto, which can be regarded as a part of a mesogen; a δ-valerolactone ring; Therefore, it has an excellent feature that a larger spontaneous polarization or a large potential spontaneous polarization is large.

Spontaneous polarization or potential spontaneous polarization induction of the present invention
Some optically active substances having a property exhibit a liquid crystal phase, and others do not exhibit a liquid crystal phase by themselves. Even if it does not show a liquid crystal phase by itself, an isotropic phase-a nematic phase-
Smectic A phase-Smectic C phase or isotropic phase-
A non-chiral liquid crystal exhibiting a nematic phase-smectic C phase phase or a composition obtained by adding 1 to 90 mol% of the composition to a ferroelectric phase (Sm
^* C phase).

Therefore, even those which do not exhibit a liquid crystal phase by themselves are useful as additives for producing ferroelectric liquid crystal compositions.

As a liquid crystal, for example, when a liquid crystal is used for a display device such as a display, it is more preferable to use a plurality of liquid crystal compounds or a mixture thereof with a compound for compounding than to use only a single liquid crystal compound. Advantageously, physical properties such as a temperature range (a temperature range showing ferroelectricity), a tilt angle, a helical pitch, a spontaneous polarization value, and a rotational viscosity can be changed.

Compounds or compositions exhibiting ferroelectricity, the above-mentioned non-chiral liquid crystals or liquid crystal compositions, etc., which can be used to form a liquid crystal composition by mixing with one or more kinds of the optically active substances of the present invention are mentioned. Any of the above-mentioned materials can be used.

[0035]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 (S) -2,2-dimethyl-5-hydroxymethyl-butyl
Synthesis of relolactone (S)-(-)-butanetriol 25 g was added to 3,3-
It was dissolved in 150 ml of dimethoxypentane, 0.1 g of p-toluenesulfonic acid was added thereto, and the mixture was stirred and reacted at room temperature for 16 hours. The solution thus obtained was poured into a saturated aqueous solution of sodium bicarbonate, and the reaction product was extracted with ether. The extract was washed with saturated saline, and the solvent was distilled off from the extract after washing. The residue was purified by silica gel column chromatography using hexane-ethyl acetate as a developing solvent to obtain 26.5 g of (S) -2,2-diethyl-4- (2-hydroxyethyl) -1,3-dioxolan. .

The whole amount was dissolved in 500 ml of benzene,
24 g of imidazole and 1 of triphenylphosphine
After stirring for 2 hours, the reaction product was extracted with ether, the extract was thoroughly washed with a 10% aqueous solution of sodium thiosulfate, dehydrated with magnesium sulfate, and the solvent was distilled off. The residue obtained by the removal was purified by silica gel column chromatography using hexane-ether as a developing solvent to give (S) -2,2-diethyl-4-.
31 g of (2-iodoethyl) -1,3-dioxolane were obtained.

In a stream of argon, at 0 ° C., a mixed solution of 9.2 g of diisopropylamine and 100 ml of anhydrous THF was added to a mixed solution.
Butyllithium solution in hexane (1.55mol / l)
80 ml was added dropwise, and then 5 g of isobutyric acid was added dropwise. After completion of the addition, the mixture was further stirred at 0 ° C. for 10 minutes, 10 ml of hexamethylphosphoramide was added, and the mixture was stirred at 10 ° C. for 30 minutes. (S) -2,2-diethyl-4
-(2-Iodoethyl) -1,3-dioxolane 16 g
Was added, and the mixture was stirred for 2 hours while maintaining the temperature at 0 ° C.

After adding 10 ml of water to the obtained reaction solution,
After adjusting the pH to 5 with 1N hydrochloric acid, the reaction product is extracted with ether, the extract is washed with saturated saline, dried over magnesium sulfate, and the residue obtained by evaporating the solvent is distilled off with hexane-hexane.
The product was purified by silica gel column chromatography using ethyl acetate as a developing solvent. The purified product was dissolved in THF. A few drops of 6N hydrochloric acid was added to this solution, and the mixture was stirred for 15 minutes to remove the protecting group. , The product was extracted with ethyl acetate, the extract was washed with saturated saline, and the solvent was distilled off from the extract to dissolve the residue obtained in benzene.
After a small amount of p-toluenesulfonic acid was added thereto and the mixture was azeotropically dehydrated, the solution was poured into a saturated aqueous solution of sodium hydrogen carbonate, and the reaction product was extracted with ether.

The extract was washed with saturated saline, dehydrated over magnesium sulfate, and the solvent was distilled off from the dehydrated extract. The residue obtained was purified by silica gel column chromatography using hexane-ethyl acetate as a developing solvent. This gave 3.5 g of (S) -2,2-dimethyl-5-hydroxymethyl-valerolactone. The NMR spectrum data of this is shown below. 1.21 (S, 3H), 1.23 (S, 3H), 1.6
２．１2.1 (m, 4H), 3.5 (brs, 1H), 3.
2. 61 (dd, J = 14 Hz, J = 6 Hz, 1H);
3. 67 (dd, J = 14 Hz, J = 4 Hz, 1H);
2 to 4.5 (m, 1H)

[0041]

[0042]

Example 3 (S) -2,2-Dimethyl-5- [4 '-(5 "-octane)
Tyloxy-2 "-pyrimidyl) -phenoxymethyl]
Synthesis of valerolactone

Embedded image 1 g of (S) -2,2-dimethyl-5-hydroxymethyl-valerolactone synthesized in Example 1 and 2- (4′-
(Hydroxyphenyl) -5-octyloxypyrimidine (1.9 g), triphenylphosphine (1.7 g) and azodicarboxylic acid (1.1 g) were dissolved in anhydrous benzene (10 ml), stirred for 12 hours, and the solvent was distilled off from the obtained solution. The obtained residue was purified by silica gel column chromatography using hexane-ethyl acetate as a developing solvent, and further recrystallized from a hexane-ethanol mixed solution to give (S) -2,2-dimethyl-5- [4 '-(5 "-octyloxy-2" -pyrimidyl) -phenoxymethyl]
1.1 g of valerolactone (melting point 141 ° C.) were obtained.

Example 4 (S) -2,2-dimethyl-5- (4 "-octyloxy)
C-4'-biphenyloxymethyl) -valerolactone
Synthesis of

Embedded image 2- (4'-hydroxyphenyl) used in Example 3
Instead of -5-octyloxypyrimidine, the same amount of 4'-octyloxy-4-biphenol was used in the same manner as in Example 3 except that (S) -2,2-dimethyl-5-methyl-5-octyloxypyrimidine was used.
(4 "-octyloxy-4'-biphenyloxymethyl) -valerolactone (melting point 112 ° C) was obtained.

[0045]

Example 6 (S) -2,2-Diethyl-5 [4 '-(5 "-octy)
Ruoxy-2 "-pyrimidyl) -phenoxymethyl] ba
Synthesis of relolactone

Embedded image By performing the same reaction using 1.7 g of n-butanoic acid instead of 5 g of isobutyric acid used in Example 1, (5S)
1.1 g of -2-ethyl-5-hydroxymethylvalerolactone was obtained. 0.5 g of this, 0.95 g of 2- (4'-hydroxyphenyl) -5-octyloxypyrimidine, 0.85 g of triphenylphosphine and 0.6 g of diethyl azodicarboxylate were added to 10 m of anhydrous benzene.
The resulting residue was purified by silica gel column chromatography using hexane-ethyl acetate as a developing solvent, and further purified with a hexane-ethanol mixed solution. By recrystallization, (5S) -2-ethyl-5- [4 '-(5 "
-Octyloxy-2 "-pyrimidyl) -phenoxymethyl] valerolactone (0.9 g) was obtained.

A solution of n-butyllithium in hexane (1.66 mol / l) was added to a mixed solution of 0.33 g of diisopropylamine and 6 ml of anhydrous THF at 0 ° C. in an argon stream.
After 1.77 ml was added dropwise and the solution was cooled to -78 ° C, 1.6 g of iodoethane was added dropwise and stirred for 2 hours.

After adding 10 ml of water to the obtained reaction solution,
Extract with methylene chloride, wash the extract with saturated saline,
By dehydrating over magnesium sulfate and evaporating the solvent, the residue obtained is purified by silica gel column chromatography using hexane-ethyl acetate as a developing solvent,
0.18 g of (S) -2,2-diethyl-5 [4 '-(5 "-octyloxy-2" -pyrimidyl) -phenoxymethyl] valerolactone (melting point: 101 DEG C.) was obtained.

Example 7 (S) -2,2-dimethyl-5 [4 '-(5 "-octy)
-2 "-pyrimidyl) -2'-fluorophenoxime
Synthesis of [tyl] valerolactone

Embedded image 2- (4'-hydroxyphenyl) used in Example 3
(S)-in the same manner as in Example 3 except that the same equivalent of 2- (4'-hydroxyphenyl) -5-octylpyrimidine was used instead of -5-octyloxypyrimidine.
2,2-dimethyl-5 [4 '-(5 "-octyl-2"-
Pyrimidyl) -2′-fluorophenoxymethyl] valerolactone (melting point 81 ° C.) was obtained.

[Embodiment 8](S) -2,2-dimethyl-5- [4 '-(5 "-
(4 "'-octylphenyl) -2" -pyrimidyl) fe
Synthesis of [Noxymethyl] valerolactone

Embedded image 2- (4'-hydroxyphenyl) used in Example 3
(S) -2 in the same manner as in Example 3 except that the same equivalent of 2- (4′-hydroxyphenyl) -5- (4′-octylphenyl) pyrimidine was used instead of -5-octyloxypyrimidine. , 2-dimethyl-5- [4 '-(5 "
-(4 "'-octylphenyl) -2" -pyrimidyl) phenoxymethyl] valerolactone (melting point 131 ° C, clearing point 171 ° C) was obtained.

Example 9 (S) -2,2-dimethyl-5- [4 ′-(4 ″ ′-de)
Siloxyphenoxycarbonyl) phenoxymethyl] ba
Synthesis of relolactone

Embedded image 2- (4'-hydroxyphenyl) used in Example 3
In the same manner as in Example 3 except that the same equivalent of 4- (4'-decyloxyphenoxycarbonyl) phenol was used instead of -5-octyloxypyrimidine, (S) -2,
2-Dimethyl-5- [4 ′-(4 ′ ″-decyloxyphenoxycarbonyl) phenoxymethyl] valerolactone (melting point 92 ° C.) was obtained.

Example 10 The following compounds were mixed at the following mixing ratio to obtain a liquid crystal composition.

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This composition shows the following phase transition:

(Equation 1)

In the above, Cryst is a crystal, SmC
Indicates a smectic C phase, N indicates a nematic phase, and a number near the arrow indicates a transition temperature (° C.) to the phase. This liquid crystal composition is not a ferroelectric liquid crystal and therefore does not show spontaneous polarization because it is composed of only the non-chiral compound.

By mixing 98 mol% of this composition and 2 mol% of the optically active substance obtained in Example 3 , a ferroelectric liquid crystal composition was obtained. This ferroelectric liquid crystal composition has a
Shows Sm ^* C phase in the temperature range up to 9 ° C,
, A chiral nematic phase at 68 to 78 ° C., and an isotropic liquid at higher temperatures.

Separately, a 2 μm-thick cell provided with a transparent electrode which is coated with a polyimide as an alignment treatment agent, lapping the surface and having a parallel alignment treatment is prepared, and this ferroelectric liquid crystal composition is injected into the cell. A ferroelectric liquid crystal device was produced.
This element was placed between two orthogonal polarizers, and an electric field was applied. It was observed that the intensity of the transmitted light was changed by the application of ± 20 V, and the response time was calculated from the change.
It was 85 μsec at 5 ° C.

Example 11 A ferroelectric liquid crystal composition was obtained by mixing 98 mol% of the non-chiral liquid crystal composition obtained in Example 10 and 2 mol% of the optically active substance obtained in Example 6. This ferroelectric liquid crystal composition shows an Sm ^* C phase in a temperature range from around room temperature to 59 ° C.
The liquid became an SmA phase at 9 to 67 ° C., a chiral nematic phase at 67 to 77 ° C., and an isotropic liquid at higher temperatures.

When the response time of this composition was determined in the same manner as in Example 5, it was 99 μsec at 25 ° C. Also,
The helical pitch of the cholesteric phase was 30 μm at 69 ° C.

Example 12 (S) -2,2-dihexyl-5- [4 ′-(5 ″ -O
Octyloxy-2 ''-pyrimidyl) phenoxymethyl
Synthesis of valerolactone By using α-hexylheptanoic acid instead of isobutyric acid used in Example 1 and hexamethyldisilazane instead of diisopropylamine, the same reaction was carried out to obtain (S) -2, 2-dihexyl-5- [4 ′-(5 ″
-Octyloxy-2 ″ -pyrimidyl) phenoxymethyl] valerolactone.

Example 13 (S) -2,2-didecyl-5- [4 ′-(5 ″ -octane)
Tyloxy-2 ''-pyrimidyl) phenoxymethyl
Synthesis of Relolactone The same reaction was carried out using α- decylundecanoic acid instead of isobutyric acid used in Example 1 and hexamethyldisilazane instead of diisopropylamine, to obtain (S) -2,2. -Didecyl-5- [4 '-(5''-
[Octyloxy-2 ″ -pyrimidyl) phenoxymethyl] valerolactone.

As described above, the optically active substance of the present invention, which exhibits liquid crystal properties, exhibits high spontaneous polarization as a ferroelectric liquid crystal, has no coloration, and has high chemical stability such as hydrolysis resistance. It shows excellent performance of excellent and light stability, and even if it does not show liquid crystallinity, it can be mixed with a non-ferroelectric liquid crystal composition as an additive to make a ferroelectric liquid crystal composition, or as a ferroelectric liquid crystal composition. When used as a compounding component in a dielectric liquid crystal composition, it enhances the spontaneous polarization of the composition, has an effect on improving the response speed, does not color the composition at the time of addition or compounding, and chemically or chemically converts the composition. The liquid crystal composition of the present invention exhibits an excellent property of not deteriorating the stability to light, and also has excellent performance as described above.

Continuation of the front page (56) References JP-A-59-164788 (JP, A) JP-A-3-128371 (JP, A) JP-A-4-211678 (JP, A) Chem. Pharm. Bull. , 19 [11] (1971) pp. 2417-2419 J.P. Am. Chem. Soc. , 103 [23] (1981) pp. 6856-6683 Planta Med. , 49 [4] (1983) pp. 240-243 Chirality, 2 [1] (1990) pp. 16-31 (58) Field surveyed (Int. Cl. ⁶ , DB name) C07D 309/30 C07D 405/00-405/12 REGISTRY (STN) CA (STN)

Claims (3)

(57) [Claims] (1) A δ-valerolactone ring represented by the formula (1)
Light with a spontaneous polarization or potential spontaneous polarization inducing
Active compounds. Embedded image (Wherein, R ₁ is a straight-chain or branched-chain alkyl group having 1 to 18 carbon atoms, a straight-chain or branched-chain alkenyl group having 1 to 18 carbon atoms, A linear or branched alkoxyalkyl group of the formulas 1 to 18, or one of the hydrogen atoms among these substituents
When at least one is halogen-substituted and has a structure capable of having an optically active group, it indicates that it may be an optically active group or a racemic form ;
₂ is an alkyl group having 1 to 18 carbon atoms , X is a single bond,
-O -, - COO- or -OCO- indicates, Y is a single bond, -OCO- or -OCH ₂ - indicates, A is ## STR2 ## And B, B ′ and B ″ each represent hydrogen, halogen, cyano group, methyl group, methoxy group or trihalomethyl group, V represents a single bond, —CH ₂ O—, —OCH ₂ —, —COO
-Or -OCO-, and * indicates that the carbon to which it is attached is an asymmetric carbon. ) 2. The intermediate for producing an optically active compound according to claim 1, which has a δ-valerolactone ring represented by the following formula (3 ). Embedded image (In the formula, R ₂ is an alkyl group having 1 to 18 carbon atoms, and * represents the above-mentioned meaning.) 3. A mixture of at least one optically active compound according to claim 1 and at least one non-chiral liquid crystal.
A ferroelectric liquid crystal composition comprising: