DE1232571B - Process for the preparation of lactones of saturated aliphatic delta-hydroxymono- or -dicarboxylic acids with 6 to 20 carbon atoms - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT LETTERING

Int. Cl .:

Number:

File number:

Registration date:

Display day:

Issue date:

C07d

German class: 12 ο -11

R23952IVb / 12o
August 27, 1958
19th January 1967
17th August 1967

The patent specification corresponds to the patent specification

The present invention relates to a process for the preparation of saturated aliphatic lactones ^ -Hydroxycarboxylic acids having 6 to 20 carbon atoms, characterized in that one Cyclohexaridione- (1,3) or its derivatives of the general formula

CHR

/ \
RCH C = O

RCH HCR

O ^Γ 5

in which R is a hydrogen atom, a saturated or olefinically unsaturated hydrocarbon radical 1 to 14 carbon atoms and in which preferably at most two R does not have any hydrogen atoms mean, or aldehyde condensation products of the general formula

R-C C-OH H HO-C C-R

R-C C C C -C C-R

\ _r / IV /

1 R 1

OH

OH

in the R in the group —CHR— preferably means a hydrogen atom by simultaneous treatment with aqueous alkali hydroxide under Pressure at elevated temperature and catalytic hydrogenation and subsequent acidification in the corresponding (5-hydroxycarboxylic acids and these in the usual way by briefly heating in their Lactones transferred.

It was already known (see "Chemical Reports", Vol. 90 [1952], pp. 61, 290, 1061) that cyclohexanedione- (1,3) and its alkyl-substituted derivatives are converted into the corresponding r $ -ketocarboxylic acids by alkali cleavage can be. It was also known that the carbonyl groups of the diones of the type described can easily be converted into hydroxyl groups by catalytic hydrogenation. It was found that the rate of reaction of this hydrogenation considerably increases the process for the production of lactones
saturated aliphatic <5-hydroxymonö- or
-dicarboxylic acids with 6 to 20 carbon atoms

Patented for:

Unilever N.V., Rotterdam (Netherlands)

Representative:

Dr.-Ing. H. Negendank, patent attorney,

Hamburg 36, Neuer Wall 41

Named as inventor:
Dr. Karl Rosenmund,
Dipl.-Chem. Hartwig Bach, Kiel

is greater than that of alkali splitting. Therefore the production of (^ -hydroxycarboxylic acids from Dions so far carried out in a two-step process, namely by producing the ^ -Ketocarboxylic acids and their catalytic hydrogenation, since it was not thought possible that Combine hydrogenation with alkali splitting.

It has now surprisingly been found that Dione of the type described above by simultaneous Hydrogenation and alkali cleavage in a yield of about 80% and more in the corresponding ^ -Hydroxycarboxylic acids can be converted, while so far by the usual two-step process far lower yields of about 60% could be achieved.

A 2-substituted cyclohexanedione- (1,3) in which the substituent is an alkyl, alkenyl or alkylidene group having 2 to 8 carbon atoms, as well as of the corresponding derivatives of resorcinol. The substituent is preferably buten-2-yl-1 or Hexen-2-yl-l.

Of the aldehyde condensation products, which are also used as starting material the condensation product of formaldehyde with resorcinol, i. H. Methylene diresorcinol, preferred.

The simultaneous hydrogenation and alkali cleavage is preferably carried out at a temperature of 110 to 150 ^° C., the hydrogen pressure being between 50 and 70 at.

■ 709 653/301

The free ^ -hydroxycarboxylic acids are removed from the reaction mixture by acidification at lower Temperature released and converted into their lactones by brief heating.

The lactones obtained can be used in particular as aromatic substances for perfumery and pharmacy as well find use as intermediates.

The following examples explain the process according to the invention in more detail.

example 1

IO

log cyclohexanedione- (1,3) are dissolved with Hg caustic soda in 100 cm ^{3 of} water and stirred at 120 ° C and 30 to 40 atm. H2 pressure in the presence of Raney nickel for 30 hours. The 5-hydroxyhexanoic acid-1-lactone is obtained by acidification, brief heating and etherification. Bp 15 = 118 to 120 ° C; Yield: 83%.

20 Example 2

A solution of 15.4 g of 1-propylcyclohexanedione (2.6), 16 g of caustic soda and 144 cm ^{3 of} water is stirred for 30 hours in the presence of Raney nickel at 120 ° C. and 50 to 70 _{atmospheres H 2 pressure.} The catalyst is filtered off, the oxyacid is set free by acidification and lactonized by brief heating. The (5-hydroxynonanoic acid lactone is extracted with ether and distilled. Bp 12 = 145 to 146 ° C; yield: 86%.

This lactone is obtained from l-allylcyclohexanedione- (2,6) in the same way and in the same way.

Example 3

35

11.8 g of methylenebisdihydroresorcinol and 8 g of caustic soda are stirred in 70 cm ^{3 of} water for 30 hours at 120 ° C. and 50 to 70 _{atmospheres H 2} pressure in the presence of Raney nickel. After filtering off the catalyst, the 4,8-dihydroxyundecanedicarboxylic acid-l, ll-dilactone is isolated by acidification, brief heating and etherification of the acidic solution. Bp 0.33 = 221 to 223 ° C; Yield: 82%.

45

Claims (3)

Patent claims: 1. Process for the preparation of lactones of saturated aliphatic r5-hydroxymono- or dicarboxylic acids with 6 to 20 carbon atoms, characterized in that one Cyclohexanedione (1.3)
general formula or
CHR
\ seme derivatives of RCH \
C = O RCH
\ HCR
/ \ . /
C. O in which R is a hydrogen atom, a saturated or unsaturated hydrocarbon radical with 1 represents up to 14 carbon atoms and in which preferably at most two R does not have any hydrogen atoms mean, or aldehyde condensation products of the general formula R-C R- C-OH H HO-C C-R Il C-R OH OH in the R in the group - CHR - preferably means a hydrogen atom by simultaneous treatment with aqueous alkali hydroxide and catalytic hydrogenation under pressure at elevated temperature and subsequent acidification in the corresponding hydroxycarboxylic acids and these in the usual way by brief heating in their Lactones transferred. 2. The method according to claim 1, characterized in that starting products are used, in their general formula R is buten-2-yl-1 or hexen-2-yl-1-. 3. The method according to claim 1 and 2, characterized in that the simultaneous alkali treatment and hydrogenation at a temperature of 110 to 150 ° C and a hydrogen pressure from 50 to 70 at. Considered publications:
German Auslegeschrift No. 1 030 327,
030 329.