Dicarboxylic acids from ozonolysis of cycloalkenes

Abstract

The "superior" method for the synthesis of dicarboxylic acids by ozonolysis of cycloalkenes with 1 molar equiv of ozone in an ether-type solvent, followed by hydrogenation over Lindlar's catalyst, has been found not to yield dicarboxylic acids directly, as claimed in the Soviet literature,1 2"4 unless excess ozone is employed. The peroxidic ozonolysis products obtained by us have been characterized and are quite different from those reported by the Russians. Thus, their mechanisms do not appear to be applicable. Ozonolysis of cycloalkenes in an acetic acid-formic acid mixture, followed by further oxidation with molecular oxygen, is a much better method for dicarboxylic acid syntheses.Recently, curious reports have come from the Soviet literature1"4 concerning the ozonolysis of cycloalkenes and 1-alkenes. According to Odinokov and co-workers,1"3 ozonolysis in etheror ester-type solvents (e.g., diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and various acetals) with one molar equiv of ozone, followed by hydrogenation over Lindlar's catalyst (Pd-CaC03-PbO), produces, from cycloalkenes, high yields of the corresponding dicarboxylic acids and, from 1-alkenes, monocarboxylic acids. Most of the work was done with cyclohexene and cyclooctene. The corresponding dicarboxylic acid reportedly crystallizes immediately upon evaporation on the reaction mixture. Odinokov et al.2,3 state that if any one of the essential reagents, an ethereal or ester-type solvent, Lindlar's catalyst, or hydrogen, is omitted, the ozonolysis affords only dialdehydes or aldehyde acids. The dicarboxylic acid yield reportedly is increased if a small amount of methanol (2 molar equiv) is present in the solvent.

Electrochemical oxo-functionalization of cyclic alkanes and alkenes using nitrate and oxygen

“…In contrast to these, metal-free processes are also known. For example, via hypervalent iodine species in combination with peracids or oxone 32 , 33 , or classically, via the ozonolysis reaction 34 .…”

Electrochemical oxo-functionalisation of cyclic alkanes and alkenes using nitrate and oxygen

“…In contrast to these, metal-free processes are also known. For example, via hypervalent iodine species in combination with peracids or oxone 32,33 , or classically, via the ozonolysis reaction 34 .…”

Novel Ozone-Mediated Cleavage of the Benzhydryl Protecting Group from Aziridinyl Esters

“…9 However, there are reports of ozonolysis carried out in ethereal solvents, 10 ethyl acetate, and alcoholic solvents. 11 Thus we decided to screen a number of different solvents for the deprotection of aziridine 3e, and the results are shown in Table 2. There was not a big difference between chlorinated solvents and ethyl acetate and methanol, but the ethereal solvents did not give any of the N-H aziridine 6e.…”

“…Typically chlorinated solvents are used in ozonolysis reactions . However, there are reports of ozonolysis carried out in ethereal solvents, ethyl acetate, and alcoholic solvents . Thus we decided to screen a number of different solvents for the deprotection of aziridine 3e , and the results are shown in Table .…”