Experimental and Computational Studies on Substituent Effects in Reactions of Peracid–Aldehyde Adducts

Dihydroperoxidation facilitates the conversion of lipids to aldehydic products via alkoxyl radicals

“…The enhancement of formation of 2-(8 0 -hydroxyoctanoyl)-PC 11 relative to 10 by atocopherol (Compare Fig. 1B and C) confirms the involvement of alkoxyl radical g. Decarboxylation of the peracid intermediate involved in the conversion of aldehyde-PC 4 to 2-(9 0 -carboxy-nonanoyl)-PC (m/z 694) should also afford alkyl radical b, since such decarboxylation accompanies the predominant Baeyer-Villiger oxidation (Lehtinen et al, 2000). Hence, suppression of formation of 4 by a-tocopherol (vide supra) should result in suppression of formation of 10 by the latter mechanism.…”

“…Carbonyl groups in aldehydic products were confirmed by derivatization with methoxylamine hydrochloride (Onyango et al, 2004). Aldehydic lipids are readily oxidized to the corresponding acids (Lehtinen, Nevalainen, & Brunow, 2000;Onyango et al, 2004). This involves conversion of an aldehyde to a peracid derivative whose Baeyer-Villiger reaction with another aldehyde molecule gives two molecules of acid (Lehtinen et al, 2000).…”

“…Aldehydic lipids are readily oxidized to the corresponding acids (Lehtinen, Nevalainen, & Brunow, 2000;Onyango et al, 2004). This involves conversion of an aldehyde to a peracid derivative whose Baeyer-Villiger reaction with another aldehyde molecule gives two molecules of acid (Lehtinen et al, 2000). Peaks corresponding to acids derived from aldehydes 4-7 are found at m/zs 694, 766, 748, and 750, respectively (Fig.…”

Efficient Baeyer-Villiger electro-oxidation of ketones with molecular oxygen using an activated carbon fiber electrode in ionic liquid [bmim][OTf]

“…In addition, in order to examine a greater range of ketones to better illustrate the scope and limitations of the method, we investigated the reactions with long carbon chain ketones such as 1-(p-tolyl)butan-1-one, 1-(p-tolyl)hexan-1-one, and pentan-2-one (Table 2, entries 11, 12 and 19), excellent yields of the expected esters were obtained. According to the literatures [51][52][53] and the observations in our reactions, taking the electrocatalytic oxidation of acetophenone with O 2 as an example, a possible mechanism is proposed (Scheme 2). In the reaction, the electro-catalytic system equipped with ACF as anode and Pt cathode in [bmim][OTf] electrolyte can generate singlet oxygen (1) by visible constant current of 30 mA electro-catalysis of O 2 (triplet state).…”

Matrix effect on the degradation of fragrant aldehydes: oxidation versus chlorination in an antiperspirant formulation

“…However, in all cases, the corresponding acid which results from an autoxidation process is the main product ranging from 23.6% (for Floralozone) to 86.3% (for valeraldehyde), besides 2-chloro aldehydes and a series of ketones, alcohols, esters, olefins and chlorinated compounds which result from CÀC cleavages. It is noteworthy that ester formate, which can be expected as an autoxidation product resulting from the Baeyer-Villiger rearrangement, [11,17] has only been detected for 2-ethyl hexanal 7 but it does not exceed 1%. By analogy with Lilial 3, we deduced that the main chlorinated product resulting from the addition of a chlorine atom on the other aldehydes is the corresponding a-chlorinated aldehyde for which the percentage varies from 1.3% in the case of Bourgeonal 1 to % 3.4% for 2-ethyl hexanal 7.…”