DE667156C - Process for the preparation of alkylated cyclopentenones - Google Patents

Description

It has been found that treatment of alkylated butyrolactones with strong sulfuric acid of at least 78% H ₂ SO ₄ content, preferably at elevated temperature, gives new cyclic ketones derived from cyclopentenone. This way of formation is new and surprising.

The hitherto unknown compounds obtained according to the invention are very stable Substances that have a strong odor and are used as a fragrance can.

The butylcyclopentenone obtained from amylbutyrolactone is one In its pure state it has a very strong odor, the odor of which is that of the natural one Jasmons is very similar, but at the same time smells of carvone.

The hexylcyclopentenone can be produced by treating the undekalactone with strong sulfuric acid of at least 78 ⁰ / _u H ₂ SO _{4 content.}

It has been established by elemental analysis and by examining the ge ^j by oxidation products formed, that the compounds according to the invention have the following structure:

= 0

The hexylcyclopentenone has a structure similar to that of natural jasmone is related and has the same number of carbon atoms as jasmone. It makes a difference differs from jasmine in that the latter substance has a methyl group in the Cyclopentenone ring and a double formation in the alkyl group adjacent to the ketone group contains. It is isomeric with the dihydrojasmon and can therefore be called dihydroisojasmon are designated.

The dihydroisoj asmon has a very strong jasmine odor and can be used in place of the Jasmons and dihydro] asmons are used for perfumery purposes. It is a colorless liquid, the following physical Has constants or properties:

D15

Refraction n _d 15 °

J ^ Pö to β

F. des Semicarbazone ..

0.921,
1.4780,

102.5 °,

i87bisi88 °.

The Dihydroisojasmon combines in the warmth with sodium bisulfite and can from the bisulnt compound is recovered in a known manner by treatment with alkalis will.

If you start from other alkylated butyrolactones, the higher or lower homologues of Dihydroisoj asmon, all characterized are that they contain a single saturated alkyl group in the cyclopentenone ring.

The production of Dihydroisojasmon, which has the following structure,

C ₆ H ₁₃
= O ■ '■

can take place according to Examples ι and 2 Examples

i. 500 g Undekalactön be treated for 15 minutes with 750 g ioo ° / ₀ sulfuric acid with vigorous stirring at a temperature of 90 ^0th The heat developed during the reaction increases the temperature to 100 ° and this temperature is maintained for 15 minutes. The reaction mixture is poured onto ice and extracted with gasoline or ether. The gasoline or ether solution is neutralized and, after the solvent has evaporated, treated with aqueous potassium hydroxide solution in order to remove the unchanged undecalactone. The product is distilled in vacuo, purified using the bisulfite compound in a manner known per se and finally distilled again in vacuo. Yield about I2 ° / _O.

In the same manner 2. Using the procedure of Example 1, with the difference that a mixture of 7.5 parts by weight of oleum having ^x S ° / o SO ₃ and 22.5 parts by weight of sulfuric acid is used instead ioo ° / ₀ sulfuric acid. The mixture of lactone and acid is not heated, but ^{left to itself at 150} for 24 hours. The reaction product is worked up in the manner described in Example 1, the he ^ ylcyclopentenone being obtained, likewise in good yield. The sulfuric anhydride can be replaced by phosphorus pentoxide in quantities of 0.5 to 10 g, with good results also being achieved. Yield about 8%.

3 x S ⁰⁰ S Amylbutyrolacton selected from ß, j in a known manner is gestures made -Nonylensäure /, during 5 minutes at he ioo ° not exceeding temperature jzugsweise at 90 to ioo °, with stirring ■ '- 750g ioo ° / ₀ iger sulfuric acid treated. The reaction mixture is then poured onto 1 kg of ice, taken up in ether, separated from the aqueous sulfuric acid and neutralized. The reaction mixture consisting of amylbutyrolactone, butylcyclopentenone and resinous condensation products is now treated with caustic solution to remove the amylbutyrolactone; the ether solution is then treated in a known manner with a sodium bisulfite solution, the butylcyclopentenone formed being converted into the corresponding bisulfite compound. The ketone is liberated from the bisulfite compound with alkali and, after the solvent has evaporated, purified by vacuum distillation.

The butylcyclopentenone obtained in this way has the following properties:

Kp ₂ to 3 .... 73 °,

F. of the semicarbazone ....... 197 ⁰ .

Yield about I2 ° / _O.

Claims (2)

Patent claims: 1. Process for the preparation of alkylated cyclopentenones ^ characterized in that alkylated butyrolactones are treated, preferably at elevated temperature, with sulfuric acid of at least 78% H ₂ SO ₄ content. ■ 2. Process for the preparation of dihydroisojäsmon, characterized in that undekalacton is treated, preferably at elevated temperature, with sulfuric acid of at least 78 _{% H 2} SO ₄ gel.