10- -5,8-decadienoic

Another useful compound is the 1 2 telomer of malonate and butadiene, 137. The first example is the synthesis of pellitorine (138), a naturally occurring pesticide (126). The terminal double bond was hydrogenated selectively with RuCl2(PPh3)3 as a catalyst. Partial hydrolysis afforded the monoester, which was treated with PhSeSePh to displace one of the carboxyl group with phenylselenyl group. Oxidative removal of the phenylselenyl group afforded 2,4-decadienoate (139), which is converted to pellitorine (138) ... 

The components of the sex pheromone from female nettle caterpillars Darna trima and Darna bradleyi (Lepidoptera Limacodidae) were identified. The compounds from D. trima were 2-methylbutyl-(A )-7,9-decadienoate (A) and ( )-2-hexenyl ( )-7,9-decadienoate (B) and from D. bradleyi were identified as methyl (T)-7,9-decadienoate (C) and isobutyl (.ff)-7,9-decadienoate (D). In Malaysia, (5 )-2-methylbutyl- E)-7,9-decadienoate in combination with B proved to be essential and synergistic pheromone components for attraction of males in field tests. (i )-2-methylbutyl- ( )-7,9-decadienoate had no behavioral activity. Compound D singly attracted male D. bradleyi, but the addition of C and D in a ratio of 1 10 significantly enhanced attractiveness of the bait. ... 

This enzyme [EC 5.2.1.5] catalyzes the interconversion of 9-cK,12-d5 -octadecadienoate and 9-d5, ll-fran5 -octa-decadienoate. 

ETHYL (E.Z)-2,4-DECADIEN0ATE (2,4-Decadienoic acid, ethyl ester, (E,Z)-)... 

Ethyl (E,Z)-2,4-decadienoate has been prepared in several ways (a) the addition of lithium d1-( Z)-1-heptenylcuprate to ethyl proplolate (90% yield, 95% purity 27-32% overall yield based on (Z)-l-bromoheptene) (b) the reaction of 1-heptenylmagnesium bromide with ethyl (E)-P-(N,N-diethylamino)acrylate (32% yield, 89% purity), (c) the Wittig reaction of hexyltriphenylphosphonium bromide with ethyl (E)-4-oxo-2-butenoate (58% yield, 85% purity). These known methods Involving the use of organometallic reagents need anhydrous conditions at low temperatures (-8° to -40°C). The separation of triphenylphosphine oxide from the reaction mixture in a Wittig reaction is occasionally not easy. 

The present procedure offers an experimentally simple and less expensive preparation of ethyl (E,Z)-2,4-decadienoate under essentially neutral conditions. It allows large scale preparation since the starting iraterlals are not sensitive to air or moisture. In addition, the reaction proceeds stereoselactively, and the yields of product are generally high. Several examples are listed in Table 1 to show the scope of the method. 

NT530 Chuman, T., and M. Noguchi. Isolation of new terpenoid acids (-f-d-me-thyl-6-isopropyl-9 OxO 2E,4E decadienoic acid and d-isopropyl-h-oxo-ZZ-hep-tenoic acid from Turkish tobacco. Agr Biol Chem 1975 39 1169. 

CH3(CH2)4CH = CHCH = CHC00CH2CH3, C12H20O2, Mr 196.29, bp6i> 70-72 °C, has been identified in pears and has the typical aroma of Williams pears. Synthesis of ethyl 2-trans-4-cw-decadienoate starts from cis-l-heptenyl bromide, which is converted into a 1-heptenyllithium cuprate complex with lithium and copper iodide. Reaction with ethyl propiolate yields a mixture of 95% ethyl 2-trans-A-cis- and 5% ethyl 2-tranx-4-tranx-decadienoate. Pure ethyl 2-trans-A-cis-decadienoate is obtained by fractional distillation [25]. A biotechnological process for its preparation has been developed [26]. 

Butyl acetate Pentyl acetate Hexyl acetate 2-Methylbutyl acetate Hexyl propane ate Ethyl butanoate Butyl butanoate Hexyl butanoate Methyl 2-methylbutanoate Ethyl 2-methylbutanoate Propyl 2-methylbutanoate Butyl 2-methylbutanoate Hexyl 2-methylbutanoate Ethyl hexanoate Ethyl octanoate Ethyl ( )-2-octenoate Methyl ( ,Z)-2,4-decadienoate Ethyl ( ,Z)-2,4-decadienoate... 

Ethyl (2E,4Z) decadienoate Pear 300 Bartlett, Williams pear... 

The flavour of distillates from apple and pear is characterised by typical aroma compounds from these fruits formed by enzymatic degradation of fatty acids to C6-fragments like hexanol, trans-2-hexenol, as well as ethyl esters and acetates of hexanoic acid. In distillates of pears, especially of the variety Bartlett pear, the characteristic pear flavour is mainly dominated by the ethyl and methyl esters of frans-2-czs-4-decadienoic acid and trans-2-trans-A-decadienoic acid [27-29], The biogenesis of these monounsaturated, diunsaturated, and triunsaturated esters may be explained by -oxidation of unsaturated linoleic and linolenic acid in the fruits. The sesquiterpene compound a-farnesene, which is formed during postharvest ripening and storage of Bartlett pears [28], shows that quality and intensity of distilled pear spirits is mainly influenced by the quality and degree of ripeness of the fruits. 

Gatfield et al. [44] reported in 2001 a method to produce natural ethyl E,Z)-2,4-decadienoate, the impact compound of pear. Immobilised lipase from Candida antarctica is capable of transesterifying Stillingia oil in the presence of ethanol. By this process, a complex mixture of ethyl esters is generated. By fractional distillation, the ethyl ester of ( ,Z)-2,4-decadienoate can be isolated from the mixture in a total yield of about 5% and with a high degree of purity. As only... 

In 2004, Ley et al. [45] showed a stereoselective enzymatic synthesis of cis-pellitorine [N-isobutyldeca-(2 ,4Z)-dienamide], a taste-active alkamide naturally occurring in tarragon. The reactants were ethyl ( ,Z)-2,4-decadienoate— the pear ester described before—and isobutyl amine. The reaction is catalysed by lipase type B from Candida antarctica (commercially available), which shows a remarkable selectivity towards the 2 ,4Z ester. The yield was about 80%. 

A. Fthyl 3,4-decadienoate (1). A 300-mL, round-bottomed flask equipped with a reflux condenser is charged with 12.1 g (0.096 mol) of l-octyn-3-ol (Note 1), 100 g (0.616 mol) of triethyl orthoacetate (Note 2), and 0.24 g (3.2 mmol) of propionic acid. The solution is heated at 140-150°C in an oil bath. Every 2 hr, the ethanol produced is removed under reduced pressure with a rotary evaporator, and then 10 g (0.062 mol) of triethyl orthoacetate and 0.024 g (0.32 mmol) of propionic acid are added. The mixture is heated until the starting material is consumed (6-8 hr) (Note 3). Excess triethyl orthoacetate is removed under reduced pressure (Note 4). The residue is distilled under reduced pressure to give 15.4-17.2 g (82-91%) of 1 (Note 5) as a clean oil, bp 80-85°C (0.3 mm). 

Figure 7.26 The structure of the hepatotoxic cyclic heptapeptide microcystin LR. L-Arginine and L-leucine are variable amino acids. The reactive unsaturated group is indicated by the star. Abbreviations Adda, amino-methoxy-trimethyl-phenyl-decadienoic acid Mdha, methyldehydro-alanine Masp, methyl D-/so-aspartate D-Glu, D-/soglutamate D-Ala, D-alanine.

Jennings et al (228) fractionated an extract from Bartlett pears into 32 volatile components of which five were found to contribute significantly to the characteristic pear aroma. Later studies indicated that esters of trans-2 cis-4 decadienoic acid and hexyl acetate were significant components of the Bartlett pear aroma (229, 230). More recently, numerous volatiles of Bartlett pears were separated and identified including esters of methyl, ethyl, propyl, butyl, and hexyl alcohols, and Cio to Ci8 fatty acids (231, 232). 

Birgersson G., Byers J.A., Bergstrom G. and Lofqvist J. (1990) Production of pheromone components, chalcogran and methyl ( ,Z)-2,4-decadienoate, in the spruce engraver Pityogenes chalcographus. J. Insect Physiol. 36, 391-395. 

Meinwald J., Chalmers A. M., PliskeT. E. and Eisner T. (1968) Pheromones. III. Identification of trans, fra j -10-hydroxy-3,7-dimethyl-2,6-decadienoic acid as a major component in hairpencil secretion of the male monarch butterfly. Tetrahedron Letters 1968, 4893 1896. 

Polyunsaturated aliphatic alkohols, aldehydes, ketones, and esters occur as fragrance components in fats, oils, fruits and plants 158). As an example the synthesis of ethyl (2 ,4Z)-2,4-decadienoate (232, pear ester ), which is responsible for the aroma of bartlett pears 161) is given. 2,4-Diunsaturated ester 232 may be obtained by a number of highly stereoselective syntheses, a lot of them making use of the Wittig reaction. Ohloff and Pawlak condensed 4,5-epoxy-( )-2-pentenal 228 with the ylide generated from 229 (butyllithium/ether) to the alkadiene epoxide 230 which was oxidized with periodic acid to the 2,4-decadienal 231. 231 is subsequently converted with MnOj/NaCN in ethanol to the pear ester 232162) [75 % (Z)-amount of the C-4 double bond] (Scheme 44). 

ETHYL 4-CYCLOHEXYL-4-OXOBUTANOATE CYCLOHEXANEBUTANOIC ACID, Y-OXO-, ETHYL ESTER (54966-52-8), 65, 17 ETHYL CYCLOPROPYLPROPIOLATE, 66, 173,174 ETHYL (E,Z)-2,4-DECADIENOATE (3025-30-7), 66, 22, 23, 25, 28 Ethyl 3,4-decadienoate (36186-28-4), 66, 22, 28 Ethyl decanoate Decanoic acid, ethyl ester (110-38-3), 67,125 ETHYL DIETHOXYPROPANOATE PROPANOIC ACID, 3.3-DIETHOXY-,... 

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