JP2000072700A - Optically active glycol and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optically active glycol with high optical purity, and further to provide a production method therefor. SOLUTION: This optically active glycol is a compound of the formula [(n) is an integer of 2-10]. The method for producing the optically active glycol comprises reducing an optically active mevalonolactone, reacting the product with a Wittig reagent and carrying out a hydrogenation reaction of the product after the reaction with the Wittig reagent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optically active glycol useful as an intermediate material for liquid crystals, pharmaceuticals and agricultural chemicals, and a method for producing the same.

[0002]

2. Description of the Related Art At present, optically active glycols are compounds useful as intermediate materials for liquid crystals, medicines, and agriculture, and many compounds have been known so far. The present inventors have conducted repeated studies on novel optically active compounds useful for these applications, and found that optically active mevalonolactone is reduced by reducing the optically active purity, and hydrogenated after reacting with a Wittig reagent. It has been found that a 1,3-diol compound can be obtained.

Accordingly, it is an object of the present invention to provide a novel optically active glycol having high optical purity and a method for producing the same.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a compound having a specific structure and high optically active purity can be synthesized from optically active mevalonolactone.

The present invention has been made based on the above findings, and provides an optically active glycol represented by the following general formula (1) of the following [formula 2] (same as the above [formula 1]). .

[0006]

Embedded image

The present invention also relates to a method for producing an optically active glycol, which comprises reducing an optically active mevalonolactone, reacting a Wittig reagent, and then hydrogenating the glycol. It provides a method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an optically active glycol of the present invention and a method for producing the same will be described in detail.

In the optically active glycol of the present invention, n in the general formula (1) is 2 to 10, preferably n is 2 to 6.
Is a compound that is an integer of

The method for producing the optically active compound of the present invention [compound represented by the general formula (1)] is not particularly limited. For example, the optically active mevalonolactone may be reduced with a metal hydride. And then Witti
Witti known to synthesize carbonyl compounds into alkenes using reagent g (alkylidenephosphorane)
g After the reaction, a method of performing hydrogenation by catalytic hydrogenation may be used.

The optically active mevalonolactone used here is in the R form. Examples of the Wittig reagent include methylenetriphenylphosphorane, ethylidenetriphenylphosphorane, propylidenetriphenylphosphorane, and butylidenetriphenylphosphorane.

[0012]

(Synthesis example of optically active glycol of the present invention)

[0013]

Embedded image

[0014]

Embedded image

20.0 g of mevalonolactone (1.537
× 10 ^-1 mol) of THF was added. The internal temperature was adjusted to −50 ° C. or lower, and 340 ml of a dibutylaluminum hydride toluene solution (1.0 M) was slowly added dropwise.
After the addition, the mixture was stirred for 20 minutes. Reaction treatment is 10 wt% N
The reaction was carried out by dropping 40 ml of an aOH aqueous solution, slowly returning the temperature to room temperature, filtering the precipitate through celite, and removing the solvent. The yield was 15.4 g (75% yield).

[0016]

Embedded image

THF 400 ml, propyltriphenylphosphonium bromide 132.9 g (3.45 × 10 ⁻¹⁾
mol)) was placed in a well-dried flask and stirred under ice-cooling to remove potassium-t-butoxide 3.
8.7 g (3.45 × 10 ⁻¹ mol) was charged. After stirring for 20 minutes under ice cooling, the temperature was returned to room temperature, and the mixture was further stirred for 20 minutes. At this time, the reaction solution was observed to gradually change to a red-orange color, and the formation of the Wittig reagent (propylidenetriphenylphosphorane) was confirmed. Next, the obtained reaction solution was cooled on ice, and the diol obtained in the first step was washed with THF.
What was dissolved in 75 ml was dropped over about 45 minutes.
After completion of the dropwise addition, the temperature was returned to room temperature, and the mixture was stirred for 30 minutes. The reaction was confirmed by TLC. After the precipitate was filtered, the solvent was removed, and the residue was subjected to a silica gel column (developing solution CHCl3 / methanol = 9 /
Purified according to 1). The yield is 14.2 g (78% yield).
Met.

[0018]

Embedded image

14.2 g of the diol obtained in the second step
(8.97 × 10 ⁻¹ mol) was dissolved in 100 ml of methanol, and 0.356 g of a Pd / C catalyst was further added.
After slightly reducing the pressure inside the system, a balloon of H ₂ gas was attached, and the mixture was stirred at room temperature for 3 hours. After completion of the reaction, the mixture was filtered through celite to remove the solvent, and then subjected to a silica gel column (developing solution: CHCl ₃
/ Methanol = 9/1) to obtain the desired compound (colorless liquid). The yield was 14.0 g (yield 97.4).
%)Met.

The optically active mevalonolactone and the synthetic intermediate used in the above synthesis example, and the final compound obtained in the above synthesis example, have an infrared absorption spectrum (IR), optical rotation [α] _D , ¹ H-NMR And identified as the target. The analysis results are as follows.

<Analytical value of optically active (R) -mevalonolactone compound> IR (neat) 3442, 2972, 2922, 1
727, 1473, 1401, 1263, 1311, 1
071 (cm ^-1 ) Optical rotation [α] _D = -31.3 ° (concentration 100%, direct measurement, 20 ° C.)

<Analytical value of compound obtained in the first step> IR (neat) 3382, 2964, 1459, 1
378, 1257, 1104, 1071 (cm ^-1 ) Optical rotation [α] _D = + 47.18 ° (C = 2.418, chloroform solution, 29 ° C.)

<Analytical value of compound obtained in the third step> IR (neat) 3349, 2933, 2862, 1
464, 1376, 1146, 1067, 1018 (c
m ^-1 ) Optical rotation [α] _D = + 0.572 ° (C = 2.096, chloroform solution, 31 ° C.) ¹ H-NMR (CDCl ₃ ): δ value 0.90 (t, 3H); 24 (S, 3H), 1.3
1-1.83 (m, 10H), 2.14 (S, 1H),
2.58 (S, 1H), 3.88 (t, 2H)

As described above, the optically active glycol of the present invention obtained by the production method of the present invention is not only a compound useful as an intermediate material for liquid crystals, pharmaceuticals, and agricultural chemicals, but also a compound which is produced by the following carbon reduction reaction. , 2-diol compounds.

[Application Synthesis Example] The synthesis example of an optically active 1,2-diol compound useful as a liquid crystal intermediate is obtained by a carbon reduction reaction of the compound (optically active glycol of the present invention) obtained in the above synthesis example. State. As a conventional synthesis example, “Tetrahedron” 40 (8) 1313
1, 24-diol compounds synthesized from lactic acid described on pages 24 to 24 (1984).

[0026]

Embedded image

THF 120 ml, 2-nitrophenyl selenium cyanide 12.7 g (5.6 × 10 ^-2 mol), n
-Tributylphosphine 11.37 g (5.6 x 10 ^-2
mol), 6.0 g of diol (3.7 × 10 ^-2 mol)
Was charged into a reaction flask, and reacted under water cooling for about 1 hour. After the precipitate was filtered, the solvent was removed, and the residue was purified by a silica gel column using hexane / ethyl acetate as a developing solvent to obtain a selenium adduct.

Purified selenium adduct, diethyl ether
100 ml was added to 25 ml of 30% by weight aqueous hydrogen peroxide,
Stirred at room temperature for 10 hours. The precipitate was removed by filtration
Thereafter, 50 ml of water was added, and oil was separated.
wash twice with MgSO 4 _FourAfter dehydration, the solvent was removed.

[0029]

Embedded image

1.20 g of the alcohol obtained in the first step
(8.44 × 10 ⁻³ mol), 30 ml of methanol and 30 ml of methylene chloride were charged into a reaction flask, cooled to about −65 to −70 ° C. in a dry ice-methanol bath, and ozone gas was blown into the reaction flask for about 1 hour. Was. After completion of the reaction, the inside of the system was replaced with argon gas, 1.3 g of NaBH ₄ was added, and the temperature was returned to room temperature. After stirring at room temperature for 1 hour as it was, the solvent was removed, and the residue was purified by a silica gel column (developing solution: ethyl acetate / hexane = 1/4) to obtain the desired compound. The yield is 145 mg (11.8% yield).
Met. The 1,2-diol compound obtained in the second step can be reacted with paratoluenesulfonyl chloride and then treated with NaOH to synthesize an epoxy compound.

From the examples, the optically active glycol of the present invention can be synthesized, and an optically active 1,2-diol compound as a liquid crystal raw material can be produced from the optically active glycol by a carbon reduction reaction. Glycols appear to be useful as these intermediates.

[0032]

The optically active glycol of the present invention is a novel compound having a high optical purity and is useful as an intermediate material for liquid crystals, pharmaceuticals and agricultural chemicals. Further, according to the method for producing an optically active glycol of the present invention, the above-mentioned optically active glycol can be obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masafuku Irizawa 5-2-1-3 Shirahata, Urawa-shi, Saitama Asahi Denka Kogyo Co., Ltd. F-term (reference) 4H006 AA01 AA02 AB84 AC11 AC22 AC81 BD70 BE20 FC74 FE11 FG29

Claims (2)

[Claims] An optically active glycol represented by the following general formula (1): Embedded image 2. The method for producing an optically active glycol according to claim 1, wherein the optically active mevalonolactone is reduced, a Wittig reagent is reacted, and then a hydrogenation reaction is carried out. Method.