RU1773900C - Method of obtaining 1-octene-3-ol - Google Patents

Abstract

The invention relates to the production of unsaturated alcohols, in particular the preparation of 1-octene-Z-ol, which is part of the Japanese fungus and has biological activity. The goal is to simplify the process. It is carried out by hydrogenation of 3-acetoxy-1,7-octadiene with an organic solution of a mixture of diisobutylaluminium hydride and zirconium chloride, previously prepared at (-5) - (+5) ° C and their molar ratio to diene equal to (15-35) :( 0.2-0.5) :( 6-15). The mixture is then stirred at 20-30 ° C for 8-12 hours. These conditions increase the yield of the target product from 71 to 91% by reducing the number of process steps from three to one and using available reagents. 1 tab.

Description

The invention relates to an improved method for producing unsaturated aliphatic alcohols, in particular to a method for producing unsaturated aliphatic alcohols, in particular to a method for producing 1-octene-Z-ol, which exhibits biological activity, for example, as part of a Japanese mushroom.

A known method for producing 1-octene-Z-ol, which consists in the initial hydrogenation of 1-acetoxy-2,7-octadiene in a steel autoclave in the presence of a rhodium catalyst CIRh (phsPJ3 under a hydrogen pressure of 17.5 atm. To the resulting mixture, consisting of from 1-acetoxy-2-octene and 1-acetoxyoctane in a ratio of 75:25, palladium acetate Pd (OAC) 2, triphenylphosphine (PhaP), potassium acetate and a mixture of acetic acid and tertbutanol are added and heated for 3 hours at 70 ° C. After treatment with water, 3-acetoxy-1-octene is obtained in a mixture with 1-acetoxy-2-octene in a ratio of 1: 1.9. the selection step is W-acetoxy-1-octene and its hydrolysis W KOH in aqueous methanol (1: 1). 1-octen-W-ol The reaction takes place in three steps according to the scheme

t

C1Rh (PhsPb Ng

-oAc.

-oAc

Pd (oAc) z-Ph3P

oas

W

ё

N | Vj

SO O O O

Oas

The disadvantages of the known method are the preparation of the target product in 3 stages; carrying out the reaction in autoclave-type vessels under hydrogen pressure using hard-to-reach catalysts (PbzP) s, Pd (OAC) 2, PhaP; low

selectivity leading to by-products 1.

Closest to the invention is a process for the preparation of 1-octene-Z-ol, which involves the initial hydrolysis of 3-acetoxy-1,7-octadiene with an alcoholic solution of KOH in 1,7-octadiene-3-ol. To the pure 1.7-octadiene-Z-ol (1.26 g, Yummol) isolated in pure form from the reaction mixture, a solution of heptane-Vi2A N (11.0 mmol) was added dropwise at 0 ° C, while the hydroxyl group is protected with the formation of aluminum alkoxide. Then lithium aluminum hydride (LiAIH / j) (0.126 g, 3.3 mmol) and cyclopentadmenmeltitanedichloride (0.1244 g, 0.5 mmol) are added, stirred for 1 hour at 0 ° C and 12 hours at 25 ° C. After treatment with HCI, it is extracted with methylene chloride. Chromatography was carried out to give 970 mg of a mixture consisting of 1-octen-Z-ol (86%), 3-octanolols (11%), 7-octen-3-ol (3%). The total output of the process. 71% The reaction proceeds in three stages according to the scheme

oas

HE

+ 1-Vigash

OAl (i-Bu) 2 30

OAHi-BtOg

+ LiAIH

CpzTiC12

The disadvantages of the known method are that the reaction is carried out in three chemical (2 technological) steps; a relatively low yield (71%) of the method; use of hard-to-reach catalyst (CpaTICIa) 2.

The purpose of the invention is to simplify the process.

The goal is achieved by the method of producing 1-octene-Z-ol by reacting 3-acetoxm-1,7-octadiene with a mixture of zirconium chloride with diisobutylaluminum hydride preliminarily prepared in an inert organic solvent at (-5) - (+5) ° C, followed by increasing temperature to 20-30 ° C and stirring for 8-12 hours at a molar ratio of zirconium chloride, diisobutylaluminum hydride and 3-acetoxy-1,7-octadiene equal to (0.2-0.5) :( 15- 35) :( 5-15), followed by hydrolysis with acid.

A distinctive feature of the method is that 3-acetoxy-1,7-octadium is added to the mixture in an organic solvent of zirconium chloride and diisobutylaluminum hydride, previously

5 0 5

0

5

0

5 0 5

prepared at (-5) - (+5) ° С at a molar ratio of zirconium chloride, diisobutylalum hydride and

3-acetoxy-1,7-octadiene equal to (0.2-0.5) :( 15-35) :( 5-15), followed by stirring the reaction mixture at 20-30 ° C for 8-12 hours and then hydrolyzed

The invention is illustrated by the following examples.

Example 1. In a 0.1 L glass reactor mounted on a magnetic stirrer, 0.07 g (0.3 mmol) ZrCU was charged in an atmosphere of dry inert gas, 3.55 g (25 mmol) was added at 0 ° C. iso-Bu2AiH in 5 ml of hexane, then dropwise 1.68 g (10 mmol) of 3-acetoxy-1,7-octadiene, the temperature is slowly raised to 25 ° C, kept under stirring for 10 hours. After the completion of the reaction, the reaction mixture is hydrolyzed 5 % solution of HC at (-5) - 0 ° C, extracted with ether. 1.16 g (91%) of 1-octene-3-ol are obtained (selectivity 91%). IR spectrum (V,); 3350, 3085, 2940, 2870, 1650, 1005, 935, 1 H-NMR spectrum (d, ppm): 0.82 g (ZN, CH.s. J 7 Hz), 1.27 m (8H, CH2), 3.58 s (1H, OH). 3.92 m (1H, CH); 4.75-6.06 m (ZN, olefinic). M + 128.

Other examples confirming the method are given in the table.

Claims (1)

Compared with the known three-step process for the preparation of 1-octene-Z-ol by hydrolysis of 3-acetoxy-1,7-octadiene with an alcohol solution of KOH and 1,7-octadiene-3-ol, reaction with diisobutylaluminum hydride in heptane followed by reduction League aluminum hydride in the presence of cyclopentadienyl titanodichlorides this method allows to obtain the target compound from the same starting material -. Z-acetoxy-1,7-octadiene in one step by the action of available diisobutylaluminium hydride in the presence of zirconium chloride, which allows to significantly simplify the process (one step instead of three of the prototype), use available reagents and increase the yield from 71 to 82-91 % SUMMARY OF THE INVENTION Method for the preparation of 1-octene-Z-ol from 3-acetoxy-1,7-octadiene using diisobuti-pluminium hydride in an inert organic solvent followed by hydrolysis with an acid, characterized in that, for the purpose of simplifying the process, 3-acetoxy-1, 7-octadmen is added to a mixture in an organic solvent of zirconyl chloride and diisobutylaluminum hydride, previously prepared at (-5) - (+5) ° C, in a molar ratio of zirconium chloride, diisobutylaluminum hydride and 3-acetoxy-1,7-octadiene 0 , 2-0.5: 15-35: 5-15, respectively, with the last yuschim stirring the reaction mass at 20 to 30 ° C for 8-12 hours and then hydrolysed.