Reactions of Ozonides: Iii. Ozonolysis of Ethyl 10-Undecenoate in Ethanol

Abstract

Diethyl sebacate was the major product obtained by ethanolysis of the ozonization products of ethyl 10-undecenoate in the temperature range 28 to 170 ' C. Mixed esters of sebacic acid were similarly obtained, in poor to moderate yields, by alcoholysis of the ozonization product from an alkyl ester of 10-undecenoic acid in the appropriate alcohol. Sebacic acid half esters are prepared by a similar treatment of the ozonization products from 10-undecenoic acid itself. Ester formation has been shown to proceed mainly by rearrangement of an alkoxyhydroperoxide, with oxidative esterification of an aldehyde intermediate contributing to a minor degree. INTRODUCTIONOzonolytic cleavage reactions have long been used to determine the positions of the double bonds in unsaturated natural products, but relatively little was known about the mechanism of product breakdown. Knowledge concerning this mechanism has greatly increased during the last decade, largely as a result of the discovery of the reacting solvent systems, particularly aliphatic alcohols. Their use has provided considerable stinlulus for current study of the alltoxyhydroperoxides and related peroxidic compounds.I t has been established, largely by the work of Criegee, that ozonization of an olefin in a reacting solvent produces an aldehyde or a ketone, an alkoxyhydroperoxide, and other peroxidic compounds (1, 2, 3). Bailey has studied the formation and decomposition of the ozonization products of phenanthrene in methanol and has reported the forination of an aldehydo-ester in good yield under the appropriate conditions (4, 5). A methyl ester was also detected among the ozonization products of camphene (6), and acenaphthylene in methanol has been found to produce a 50% yield of methyl 8-formyl-1-naphthoate (7).

Reactions of ozonides. VI. Conditions for by-product ester production in the oxidative ozonolysis of oleic acid

“…In reacting solvents (14) ester byproduct yields were lower, and yields of the expected acid products, nonanoic acid, and azelaic acid, were near-quantitative. Performic acid oxidation of 1-alkylcycloalkene ozonization products (15,24), emulsion ozonizatioll (13) of alkenes in aqueous hydrogen peroxide, and lowtemperature ozonization (25) gave smaller yields of esters. We found that catalyzed room-temperature autoxidation of isolated ozonide o r mixed ozonization products gave somewhat lower ester yields.…”