Aleuritic acid

Composition. Shellac is primarily a mixture of aUphatic polyhydroxy acids in the form of lactones and esters. It has an acid number of ca 70, a saponification number of ca 230, a hydroxyl number of ca 260, and an iodine number of ca 15. Its average molecular weight is ca 1000. Shellac is a complex mixture, but some of its constituents have been identified. Aleuritic acid, an optically inactive 9,10,16-trihydroxypalmitic acid, has been isolated by saponification. Related carboxyflc acids such as 16-hydroxy- and 9,10-dihydroxypalmitic acids, also have been identified after saponification. These acids may not be primary products of hydrolysis, but may have been produced by the treatment. Studies show that shellac contains carboxyflc acids with long methylene chains, unsaturated esters, probably an aliphatic aldehyde, a saturated aliphatic ester, a primary alcohol, and isolated or unconjugated double bonds. 

Aleuritic acid [/2S-erytAro-9,10,16-trihydroxyhexadecanoic acid] [533-87-9] M 304.4, m 100-101 . Crystd from aqueous EtOH. Hydrazide cryst from EtOH has m 139-140°. 

Shellac [124,125] is a natural resin used in very old times for varnishes and moulding compounds. The resin secreted by the lac insect, Kerriar paca, is collected by scraping the shellac-encrusted trees found in southern parts of Asia. It consists of a complex mixture of cross-linked polyesters derived from hydroxy acids, principally aleuritic acid (9,10,16-trihydroxyhexadecanoic acid). From a structural point of view, it appears that this material can be used as a crosslinking agent and/or as a monomer for developing dentrite-like polymers. The question is whether it is possible to produce this material from shellac by controlled hydrolysis. 

Ester of aleuritic acid and laccijalaric acid C31H50O8... 

Aleuritic acid, physical properties of, 5 35t Aleurone layer, 3 567 Alexandrite, color of, 7 331 Ale yeast, 3 580... 

Shellac, which was used by Edison for molding his first photograph records and is still used as an alcoholic solution (spirit varnish) for coating wood, is a cross-linked polymer consisting largely of derivatives of aleuritic acid (9,10,16-trihydroxyhexadecanoic acid). Shellac is excreted by small coccid insects Coccus lacca), which feed on the twigs of trees in Southeast Asia. Over 2 million insects must be dissolved in ethanol to produce 1 kg of shellac. 

Aleuritic acid [533-87-3] M 304.4, m 100-101 . Crystd from aqueous EtOH. 

Macrocyclic lactonization. co-Hydroxy acids are converted into the corresponding lactones by reaction with cyanuric chloride and triethylaminc in acetone or acetonitrile at 25°.1 Isolated yields of 13-, 16-, 17-, and 19-membered lactones are 70, 68, 85, and 33%, respectively. An example is the lactonization of aleuritic acid (I) to the lactone acetonide 2. 

Stettbacher, Explosivst 19 54, 40 7)Schweiz-Sprengstoff—Fabrik A-G letter dated Dec 10, 1953 to Dr A. Stettbacher, Zurich, Switzerland and transmitted to the authors 8) PATR 2510(1958), p Ger 3 Aleurityl Azide, C,s H2,(OH),. CO. N, solid mp-dec on slow heating ca 52 expl when heated rapidly to ca 50°, insol in w petr eth sol in chlf ale and si sol in eth benz. Was prepd by refluxing aleuritic acid (9, 10, l6-trihydroxypalmitic acid), C1S H2 (OH)j-... 

Aleuritic acid pharmaceutical glaze polyvinyl acetate phtha-late shellolic acid. 

Comments component of shellac. The EINECS number for aleuritic acid is 208-578-8. 

Acetic acid Activated attapulgite Aleuritic acid d-Alpha tocopherol d-Alpha tocopheryl acetate d/-Alpha tocopheryl acetate d-Alpha tocopheryl acid succinate d/-Alpha tocopheryl acid succinate Aluminum distearate Aluminum monostearate Amylopectin a-Amylose... 

Photochemically induced decarboxylations of (phenylalkoxy)acetic acids in the presence of mercury (II) oxide and iodine and of threo-aleuritic acid in the presence of lead tetraacetate and iodine have been reported. Carbon dioxide is one of many... 

Hydrolysis of the resins will produce aldehydic acids at mild concentration of alkali ( N) using more concentrated alkalis (5N) hydroxy acids are produced, probably via the aldehydic acids. Unfortunately most of the work done in order to analyse the lac resin was carried out before the significance of the hydrolysis conditions was fully appreciated. It does, however, appear to be agreed that one of the major constitutents is aleuritic acid (Figure 30.9). 

Ci6H2g02, Mt 252.40, is not reported as being found in nature, in contrast to (Z)-7-hexadecen-16-olide, which occurs in ambrette seed oil (see p. 182) and which is also referred to as ambrettolide. It is a colorless to slightly yellow liquid, re 0 0.949 -0.957, re 0 1.477-1.482, with an intense and powerful musk odor. It is prepared by treating aleuritic acid (9,10,16-trihydroxyhexadecanoic acid) with trimethyl... 

The shellac material that is not crosslinked characteristically dissolves in a 4% borax solution. It may also be identified by a test for aleuritic acid as its main constituent as described by Hummel (Vol. 2, p. 427), which is a more complex technique. 

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