Ricinelaidic acid

B. Ricinelaidic acid S-(2-pyridyl)carlothaoate. In a dry, stoppered 10-mL flask containing a magnetic stirring bar are placed 360 mg (1.2 mmol) of ricinelaidic acid (see above), 308 mg (1.4 nmol) of 2,2 -dipyndyl disulfide (Note 5), 1 mL of benzene and 367 mg (1.4 mmol) of triphenylphosphine, and the mixture is stirred for 30 min. The resulting slurry is then dissolved in 55 mL of dry acetonitrile (Note 6). 

Ricinelaidic acid was selected for the submitted procedure because it has a moderately complex structure and can be prepared easily from commercially available technical grade rici nolle acid. This conversion represents an... 

Nizigiyimana, L., Van Den Heuvel, H. and Claeys, M. (1997) Comparison of low- and high-energy collision-induced dissociation tandem mass spectrometry in the analysis of ricinoleic and ricinelaidic acid. J. Mass Spectrom., 32 (3), 277-86. 

A similar ene reaction provides a short route to ricinelaidic acid, (E)-2, and ricinoleic acid, (Z)-2, in a 4 1 ratio. 

Meanwhile, Mukaiyama et al. [26] developed another similar procedure, by the use of 6-phenyl-2-pyridyl esters, for the synthesis of macrocychc lactones. This method has been used in the synthesis of f - - )-ricinelaidic acid lactone 40) [27]. Thus, as shown in Scheme 13, a mixture of 6-phenyl-2-pyridone, 2-chloro-l-methylpyridinium iodide 28), and triethylamine in dichloromethane was stirred at room temperature for 1 h. To this solution was added a dichloromethane solution of the hydroxy acid 38 and triethylamine under reflux over 6 h to give the activated ester 39 in 99% yield. A dichloromethane solution of 39 was added to a / -toluenesulfonic acid solution in dichloromethane under reflux over 11 h. Acid-induced lactonization led to the macrocycle 40 in 96% yield ... 

Ricinelaidic acid 9-Octadecenoic acid, 12-hydroxy-, [/ -( )]- Veratric acid Benzoic acid, 3,4-dimethoxy-... 

Fuerstner, A., Langemann, K. Total Syntheses of (+)-Ricinelaidic Acid Lactone and of (-)-Gloeosporone Based on Transition-Metal-Catalyzed C-C Bond Formations. J. Am. Chem. Soc. 1997,119, 9130-9136. 

Functionalized allyltributylstannanes can also be used in the BINOL/Ti-cata-lyzed reaction and addition of P-substituted allyl groups with heteroatoms in the side chain to aldehydes has been achieved with a high degree of enantiocon-trol [ 16]. The catalytic asymmetric allylation has been successfully applied to to -tal syntheses of the macrohdes (l )-(-i-)-ricinelaidic acid lactone and (-)-gloe-osporone [21]. 

EtAlCh, a stronger Lewis acid than Me2AlCl, with a less nucleophilic alkyl group, successfully catalyzes the ene reactions of aliphatic aldehydes with terminal alkenes. Reaction of an aliphatic aldehyde with a terminal alkene and EtAlCh in CH2CI2 for a few minutes at 0 C gives the ene adduct as a 4 1 ( ) (Z) mixture in 50-60% yield. Reaction of 9-decenoic acid with 1 equiv. of acetaldehyde and 2.2 equiv. of EtAlCh affords (69) as a 4 1 ( ) (2) mixture in 66% yield. Lactonization of the ( )-isomer provides recifeiolide. Reaction of 10-undecenoic acid with 1 equiv. of heptanal and 2.2 equiv. of EtAlCh provides a 4 1 mixture of ricinelaidic acid ( )-(70) and ricinoleic acid (Z)-(70) in 41% yield (Scheme 14).27... 

The purity of the products has been checked by capillary gas liquid chromatography of the corresponding methyl ester obtained with ethereal diazomethane solution (Carlo Erba Fractovap 20 meter glass capillary coated with UCON HB at 16Q°C). Ricinelaidic acid, mp 49-50 C, contains 4%, that with mp 51.0-51,5°C, less than 1% of rlcinoUc acid. Submitters obtained higher yields (58%, mp 49-50°C), perhaps due to better quality starting material. 

The Lewis acid-induced acylation of unsaturated fatty compounds combined with the following reactions allows the synthesis of natural products derived from fats. Acylation of 10-undecenoic acid [2a] with heptanoyl chloride gave 12-oxo-9-octadecenoic acid reduction with NaBHq afforded the racemate of ricinelaidic acid [6], a natural product (Fig. 2). 

Most of the conjugated Cig acids are trienes but a diene 0tl2t 12%) is present in Chilopsis linearis seed oil along with some other less common acids. Conjugated octadecadienoic acids result from dehydration of ricinoleic and ricinelaidic acids (Section 1.9) and from alkali isomerization of linoleic acid. Claims have been made for the formation of the 8rt0, the four 9,11 and the four 10,12 dienes by one or both of these methods. 

Resorcinol reaction for gangliosides, 281 Respiratory distress syndrome, 551 Response to injury hypothesis and smooth muscle proliferation, 539 Rhamnolipid, 40 Rheological behaviour, 332,361 Rhesus macaque milk, 168 Rhino mutant mouse, 143 Rhizophylyctis rosea, 153 Rhizopus, 151,152,154,478,479, 513 Rhodotorula, 151,152 Rice bran oil, 84,104-06,162 Rice lipoxygenase, 458 Ricin in castor bean, 57 Ricinelaidic acid, 11... 

Dehydration of a suitable precursor at high temperature under vacuo initially yielded a polyester (8), upon which pyrolysis afforded the trans-9,trans-11-18 2 isomer. For this procedure ricinoleic acid was first elaidinized, which means a transformation of the ds- double bond into a trans- double bond (9). The so formed ricinelaidic acid was then heated under vacuum at 235°C. Intermolecular esterification (estolide formation) yielded polyesters with a molecular weight of 1500 to 1600. Pyrolysis and simultaneous distillation furnished a crude product, which was recrystallized in 95% ethanol to furnish the desired trans-9,trans-W- % 2 isomer in a 35% yield. 

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