NEW PROCESS FOR THE PRODUCTION OF BETA-SPRINGENE

Abstract

The present invention relates to a process for the production of -springene of formula (I) wherein a compound of formula (II) is heated in the presence of a catalyst.

##STR00001##

Claims

1. Process to produce the compound of formula (I) ##STR00005## wherein a compound of formula (II) ##STR00006## is heated in the presence of a catalyst.

2. Process according to claim 1, wherein the reaction is carried out in at least one polar aprotic solvents (preferably DMSO).

3. Process according to claim 1, wherein the reaction of step (i) is carried out at a temperature (of 30 C.-80 C.

4. Process according to claim 1, wherein the reaction of step (i) is carried out under an inert gas atmosphere.

5. Process according to claim 1, wherein catalyst is chosen from a strong base and a transition metal complex.

6. Process according to claim 5, wherein base is chosen from the group consisting of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), Trger base (2,8-Dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine) and 1,4-Diazabicyclo[2.2.2]octane (DABCO) and the and a transition metal complex is chosen from the group consisting of Pd(PPh.sub.3).sub.4, Ni(PPh.sub.3).sub.4, Pt(PoTol.sub.3).sub.4, Pt(PPh.sub.3).sub.4, Ni(PoTol.sub.3).sub.4, Pd(PoTol.sub.3).sub.4, Pd(Palkyl.sub.3).sub.4, Ni(Palkyl.sub.3).sub.4, Pd(Palkyl.sub.3).sub.4, Ni(OPPh.sub.3)4, Pd(OPPh.sub.3).sub.4, Pt(OPPh.sub.3).sub.4, wherein alkyl means C.sub.1-C.sub.6-alkyl, which can be linear or branched.

Description

EXAMPLES

Example 1

Elimination of Acetic Acid from Geranyl Linayl Acetate

[0025] Under inert gas atmosphere, 1.4 mmol of geranyl linalyl acetate ((6E,10E)-3,7,11,15-tetramethylhexadeca-1,6,10,14-tetraen-3-yl acetate) were dissolved in 2.9 ml of anhydrous DMSO. At room temperature, subsequently 2.9 mmol (2.00 eq.) of DBU and 0.100 mmol (7 mol %) of Pd(PPh.sub.3).sub.4 were added to the stirred solution. Then, the reaction mixture was heated to 60 C. (oil-bath temperature) and stirred for 2 hours. After that, the reaction mixture was cooled to room temperature, and diluted with ethyl acetate (100 ml). The organic solution was subsequently washed with water (2100 ml) and brine (100 ml). The aqueous phase was re-extracted with ethyl acetate (3100 ml). The combined organic layers were dried over Na.sub.2SO.sub.4, filtered, and concentrated under reduced pressure. The crude product (8.27 g) was obtained as a mixture of - and -springene in a ratio of 4:1. Quantitative analysis of the crude product showed 50.4% purity for -springene (77% yield) and 13.0% purity for -springene (20% yield). The crude material was purified by column chromatography (SiO.sub.2, pentane).

Example 2

[0026] Under inert gas atmosphere, geranylgeranyl acetate (1.3 mmol) was dissolved in anhydrous DMSO (2.5 ml). With stirring DBU (2 eq.) and Pd(PPh3)4 (7 mol %) were added and the reaction mixture was warmed to 60 C. within 15 min. After 3 hours reaction time, the mixture was cooled to room temperature and transferred into a separation funnel with 20 ml of ethyl acetate. The organic phase was washed with water (220 ml) and brine (20 ml). The aqueous layers were extracted with ethyl acetate (320 ml). The combined organic layers were dried over MgSO4 and concentrated under reduced pressure. The product was obtained as an isomeric mixture of - and -springene (7:3) in 66% yield.

[0027] When using geranylgeraniol or geranyl linallol as starting material, no conversion was observed under the same reaction conditions.