PL194470B1 - Novel unsaturated terpenoid lactone and method of obtaining same - Google Patents

Abstract

A new unsaturated terpenoid lactone of formula 1 shown in the drawing. 2. A method for obtaining a new unsaturated terpenoid lactone of formula 1 shown in the drawing, characterized in that (E)-3,3,7-trimethyl-4-octenoic acid ethyl ester is hydrolyzed under basic conditions, preferably in the presence of potassium hydroxide in ethanol, to an acid, which is then iodolactonized in the next step, preferably using an aqueous solution of iodine in potassium iodide, after which the obtained d-iodo-g-lactone is converted to an unsaturated g-lactone in a reaction with 1,8-diazobicyclo[5.4.0]-7-un-decene.

Description

Description of the invention

The subject of the invention is a new unsaturated terpenoid lactone and a method for its preparation.

The raw material for the preparation of the new unsaturated terpenoid lactone is the known ethyl ester of (E) -3,3,7-trimethyl-4-octene acid (R. Obara, C. Wawrzeńczyk, J. Cosmet. Sci., 1998, 49, pp. 299) -308)

The essence of the invention is a novel unsaturated terpenoid lactone of the formula I shown in the drawing.

The process according to the invention consists in hydrolyzing (E) -3,3,7-trimethyl-4-octene acid ethyl ester under basic conditions, preferably in the presence of potassium hydroxide in ethanol, to an acid, which is then subjected to iodolactonization is preferably carried out using an aqueous solution of iodine in potassium iodide. The obtained d-iodo-g-lactone in reaction with 1,8-diazobicyclo- [5.4.0] -7-undecene, is converted into unsaturated γ-lactone of formula 1 shown in the figure.

The new compound obtained in this way is characterized by an intense aroma of coriander herb. This compound can be used in the food industry as a component of fragrance essences.

The method according to the invention is explained in more detail in an embodiment:

P r z k ł a d:

Ethyl (E) -3,3,7-trimethyl-4-oktenowego (3.6 g 0.017 mol) is subjected to basic hydrolysis using 30 cm ^{3 of} a 2.5% solution of potassium hydroxide in ethanol. The reaction mixture is refluxed for 10 hours. The ethyl alcohol is then evaporated on a rotary evaporator under reduced pressure. The residue is diluted with distilled water, then the organic impurities are extracted with diethyl ether.

The aqueous layer is acidified with 0.1 M hydrochloric acid to pH = 2, then the product is extracted with diethyl ether (4 x 50 cm ³ ). The resulting ether extract was washed with brine and dried over anhydrous magnesium sulfate. After evaporating off the solvent, 2.9 g (95% of theory) of pure acid are obtained with the following physical and spectroscopic constants:

n _D ²⁰ = ¹ 4564; ¹ H NMR ^(CDCl3) d ^{0 84} (d, J = ^6, 6 Hz, 6H, CH (CH, m 1.13 (s, 6H, ^- C ^(CH3) 2 ^-), 1.56 ( m, 1H, -CH (CH3) 2), 1.86 (t, J = 6.7 Hz, 2H, -Cl ± -CH = CH-), 2.29 (s, 2H, -CH2CO2-), 5.37 (d, t, J = 15.6 and 6.7 Hz, 1H, -CH ₃ -CH = CH-), 5.45 (d, J = 15.6, 1H, -CH ₃ -CH = CH-), 10.5 (broad signal from -COOH);

IR ^{(cm -1):} 2600 ^- 3300 (s, b), 976 ^(m).

3

The acid obtained (2.9 g, 0.016 mol) in 50 ml of diethyl ether is added to 50 ml

0.5 M sodium bicarbonate solution and stirred at room temperature for about 30 minutes. It is then heated to reflux and 200 ml of an aqueous solution of iodine (6.4 g) in potassium iodide (12.6 g) are added. The mixture is stirred and refluxed for 8 hours. After cooling, the contents of the flask are diluted with diethyl ether and shaken with sodium thiosulfate solution. The ether layer, separated, was washed with a saturated sodium bicarbonate solution and brine, and dried over anhydrous magnesium sulfate. The crude product, a mixture of 8-iodo-g-lactone (70%) and g-iodo-d-lactone (30%), is purified by column chromatography on silica gel using a mixture of hexane and ethyl acetate, v / v. 4: 1. This gives 2.7 g of d-iodo-g-lactone and 1.2 g of g-iodo-d-lactone, which is 79% of theory. The obtained iodolactones have the consistency of a thick oil. Their spectroscopic properties are as follows:

4.4-dimethyl-5- (1-iodo-3-methylbutyl) tetrahydrofuran-2-one (8-iodo-g-lactone):

¹ H NMR (CDCl3) ^{d: 0,} 79 and ^0, 92 ^{(D dd,} J = ^6, 5 Hz, 6H, CH ^(CH, 1.11 M, and ^1, 42 ^{(as in d,} 6H, - C (CH3) 2-), 1.67 (m, 2H, -CH2CHJ-), 2.31 and 1.44 (d, J - 17.2 Hz, 2H, AB system, -CH2CO2-), 3, 19 (ddd, J = 11.1, 9.4 and 3.4 Hz, 1H, -CH ₃ CHJ-), 4.36 (d, J = 9.4 Hz, 1H, -CHO-);

IR (m ^1): 1796 ⁽ s) 1172 ⁽ s, 996 ⁽ s ^);

4.4-dimethyl-5-iodo-6- (2-methylpropyl) tetrahedron-2H-pyrene-2-one (g-iodo-d-lactone):

¹ H NMR (CDCl3) ^{d: 0,} 92 and ^0, 93 ^{(D dd,} J = ^6, 4 Hz, 6H, CH ^(CH, 1.10 M and 1.14 ^{(d of as,} 6H, - C (CH3) 2-), 2.38 and 2.71 (two d, J = 17.2 Hz, 2H AB system, -CH2-CO2-), 3.92 (d, J = 10.9 Hz, 1H, -CHI-), 4.46 (td, J = 10.9 and 1.8 Hz, 1H, CH-O-);

IR ⁽ cm ^1): 1740 ⁽ s) 1172 ⁽ m, 1136 ^ 1012 ⁽ m).

PL 194 470 B1

To the thus obtained d-iodo-g-lactone (0.009 mol) in 80 ^cm3 of anhydrous benzene is added 4.4 cm @ 3 (0.029 mol) of 1,8-diazabicyclo [5.4.0] -7-undecene (DBU). The mixture is refluxed under nitrogen for 12 hours. The precipitate formed was then filtered off, the filtrate was diluted with diethyl ether, and then the ethereal solution was washed with an aqueous ammonium chloride solution and brine and dried with anhydrous magnesium sulfate. After distilling off the solvent, the crude product was purified by silica gel column chromatography using a 5: 1 v / v hexane-acetone mixture as eluent. 1.5 g of 5- (3-methylbutylidene) -4,4-dimethyltetrahydrofuran-2-one are obtained. The yield of the last step is 90% and the yield of the three-step synthesis is 48%.

The spectroscopic constants of the obtained compound are as follows:

¹ H NMR ^(CDCl3) d: ^0, 86 ^(d, J = ^6, 7 Hz, 6H, ^- CH ^{(CH3) 2), 1,} 34 ^(s, 6H, ^ (0½) ^{2) 1,} 57 ⁽ m, 1H, -CH (CH3) 2), 1.93 (dd, J = 7.9 and 7.0 Hz, 2H, -CH2CH-), 2.47 (s, 2H, -CH2CO2-) , 5.07 (t, J = 7.9 Hz, 1H, -CH2CH =);

IR ^{(cm -1): 1792,} 0 (m ^ 1472 ^ (1? 1236 (1? 1092 ^(m).

Claims (2)

Patent claims 1. A novel unsaturated terpenoid lactone of the formula 1 shown in the figure. 2. A method for the preparation of a new unsaturated terpenoid lactone of formula 1 shown in the figure, characterized in that (E) -3,3,7-trimethyl-4-octene acid ethyl ester is hydrolyzed under basic conditions, preferably in the presence of potassium hydroxide in ethanol to an acid which is then iodolactonized in a next step, preferably using an aqueous solution of iodine in potassium iodide, followed by the resulting d-iodo-g-lactone by reaction with 1,8-diazobicyclo [5.4.0] -7-un -decene, transforms into unsaturated g-lactone.