JPS593457B2 - Method for producing 9-oxoisolongifolene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to longifolene and/or isolongifoline.
9-oxoisolongifolene 5 (
9-ox-O-isolongifolene).

9-Oxoisolongifolene can be reduced to obtain a saturated isolongifolene ketone compound of high perfumery value.

Conventionally, as a method for obtaining a 10-ton compound of isolongifolene, a method of oxidizing synthesis using hydrogen peroxide, sodium dichromate, etc. in a lower fatty acid is known, but the oxidation of the present invention utilizes oxygen in the air. is sufficient to achieve the purpose, and the polar aprotic solvent used can be recovered and
5. It can be used repeatedly and does not generate waste that causes pollution problems. The reaction according to the process of the invention has high yields and a high degree of selectivity, giving it extremely advantageous features in industry compared to known processes. It is therefore an object of the present invention to provide a new method which is more economical and gives higher yields than conventional synthetic methods.

In the method of the present invention, 9-oxoisolongifolene can be obtained using either longifolene or isolongifolene as the raw material, but the yield is not so good when longifolene is used as the starting material. A method using isolongifolene as a starting material is preferred.

Therefore, in the case of longifolene, it is preferable to carry out the process of the present invention after isomerizing it to isologifoline by a known method. However, apart from this, 9-oxoisolongifolene can also be advantageously obtained by carrying out the method of the present invention on raw materials containing longifolene and isolongifolene. (I) used as raw material in the method of the invention
The chemical structural formulas of longifolene, (■) isolongifolene, and (■) 9-oxoisolongifolene as a 35 product are shown below along with numbers indicating the positional relationship. iζ0- In addition, if these compounds (1), (), and () are written in IUPAC nomenclature, they are as follows.

Typical polar aprotic solvents used in the present invention are dimethyl sulfoxide (hereinafter referred to as DMSO), dimethyl formamide (hereinafter referred to as melon), and hexamethylphosphoramide (hereinafter referred to as HMPA),
Select from these to be used. The amount of solvent to be used is preferably 5 times the amount of longifolene used as the raw material. The reaction temperature is preferably within the range of 110°C to 130°C. The standard amount of oxygen used is about 3 moles per mole of the raw material in the case of longifolene, and about 2 moles per mole of the raw material in the case of isolongifolene. The oxygen introduction rate is 1/10 volume/min of the total weight of the charged amount (raw material + 4 melt a) (for example, 30 f
3 m1/min) is the standard oxygen introduction rate. When using air, it is preferable to dry the air beforehand. DM
When SO is used, after the reaction is completed, the reaction solution is directly distilled under reduced pressure, and the solvent fraction up to about 70° C. is recovered under a reduced pressure of 10 iHg. This recovered solvent can be used repeatedly as is. Next, the degree of vacuum is increased and a fraction of 133-135°C/211Hg is collected. Examples according to the invention are shown below.

Example 1 Longiholen 5R (0
．． 025 mol) and DMSO25V were taken, and air (calcium chloride, dried by passing through sulfuric acid) was added at 3 ml/
The mixture was stirred at a temperature of 130° C. for 48 hours while being introduced at a rate of 1 minute.

The amount of oxygen introduced corresponds to 3.1 mol per 1 mol of longifolene. The reaction solution was transferred to a distiller, and fraction 22f (DMSO) up to 70°C was collected under reduced pressure of 10 uHg. Then, 211 BHg was distilled under reduced pressure to obtain fraction 2 at 133-135°C.
．． I got 55y. This was recrystallized from hexane and purified 9
-2.51y of oxoisolongifolene was obtained. The yield was approximately 47% of theory. The physical properties of the purified product are as follows. Melting point: 52-53°C [α]D: -20.4°C (C = 10%, hexane) Semicarbazone Melting point: 218-219°C IR (Cm-1):
1665 (3+), 1300 (2+), 1265 (2+
), 1170 (2+), 1124 (2+), 1082 (
2+), 920(2+), 829(2+), 830(+
) CDCl NMR (δ 3 ): 1.04 (3H,
．． S), Ppml. O9(3H,.S), 1.12(3
H,. S), 1.18 (3H,.S), 1.2-2.6
(9H,.m), 5.76 (1H,.S) Example 2 Isolongifolene 5y was placed in a 100 m1 four-necked flask equipped with a reflux condenser, thermometer, stirrer and air inlet tube.
(0.025 mol) and DMSO25? was taken, and air (calcium chloride, dried by passing through sulfuric acid) was added to the
The mixture was stirred at a temperature of 130° C. for 32 hours while being introduced at a rate of 1 minute.

The amount of oxygen introduced corresponds to 2.1 mol per 1 mol of isolongifolene. The reaction solution was transferred to a distillation vessel, and fraction 227 (DMSO) of up to 70°C was collected at a distillation vacuum degree of 10 Hg.
Then, rectification was carried out under 2 nHg to obtain a fraction of 133 to 135° C., which was recrystallized from hexane to obtain 5.137 of 9-oxoisolongifolene. The yield was approximately 96% of theory. Example 3 The reaction was carried out under the same reaction conditions as in Example 2 except that D was used instead of DMSO and a distillation vacuum of 400 Hg was used instead of 10 nHg. Obtained 5t.

The yield was about 93% of theory. Example 4 The reaction was carried out under all the same reaction conditions except that HMPA was used instead of DMSO in Example 2, and a reduced pressure of 2 tmHg was used instead of 101 tmHg, and 9-oxoisolongi 5.3y of hollen was obtained.

Claims (1)

[Scope of Claims] 1. A method for producing 9-oxoisolongifolene, which comprises oxidizing longifolene and/or isolongifolene in a polar aprotic solvent with oxygen or an oxygen-containing gas while heating. 2. The manufacturing method according to claim 1, wherein the polar aprotic solvent is selected from the group consisting of dimethyl sulfoxide, dimethylformamide, and hexamethylphosphoramide. 3. The manufacturing method according to claim 1 or 2, wherein the heating temperature is within the range of 110° to 130°C. 4. The manufacturing method according to claim 1, 2 or 3, wherein the oxygen-containing gas is air.