Periodate–permanganate Oxidations: Ii. Determination of Terminal Methylene Groups

Abstract

The periodate-permanganate oxidation of a terminal methylene (CH-C:) group can be made to produce formaldehyde in high although not quantitative yield. Since the yields compare favorably with those obtained by ozonolysis, the reagent can serve as the basis for a convenient micromethod for the estimation of terminal methylene groups. The less than theoretical yields of formaldehyde are believed mainly due to the conversion of the olefin in part to a-hydrosyaldehyde in the initial stage of the reaction. INTRODUCTIONResults were reported in our first communication in this series (12) which indicated that the periodate-permanganate oxidatioil of a terminal methylene group (I) produces, simultaneously, in the first stage of the reaction, glycol (II), ketol (111), and hydroxyaldehyde (IV). Subsequent periodate oxidation of these substances produces formaldehyde from I1 and I11 but not from IV. Glycol formation did not appear extensive in wealtly alkaline media since the oxidation of ethylene gave very nearly one mole of formaldehyde. However, oxidation of 10-undecenoic acid gave a 73% yield of formaldehyde (12). I t was therefore evident that the ltetol formation can be the preferred route and since the oxidant attaclted formaldehyde only very slowly, it was apparent that the reagent deserved attention as a means for the semiquailtitative estimation of terminal methylene groups.We now wish t o report on evidence that any attempt t o obtain a ~naximum yield of formaldehyde in the periodate-permanganate oxidation of a terminal methylene group should consider: (a) the effect of pH on the reaction route, (b) the effect of pH on the rate of the periodate oxidation of glycols and acyloins, (c) the effect of pH on the rate of the permanganate oxidatioll of formaldehyde, and (d) the solubility of the compound in aqueous media.Evidence has been obtained (12) that hydroxylatioil of the olefin is favored a t a pH of 9-10 with acyloiil formation predominating a t a slightly lower pH. On this basis, it would appear desirable t o operate a t a high pH. However, the periodate-permangallate reagent does not operate above about pH 10 (12).Also, even a t pH 10, the periodate oxidation of glycols is relatively slow (3, 14). For personal use only.

A Sphingolipid Desaturase from Higher Plants

“…One aliquot (360 g) of the peracetylated mixture of phytosphinganine and phytosphingenine isomers was de-O-acetylated (0.02 M sodium methoxide, 1 h at room temperature) prior to lead tetraacetate oxidation (22). The resulting aldehydes were extracted with chloroform, reduced with lithium aluminum hydride, and separated into two aliquots; one (200 g) was used to produce the nicotinates (22), and the other (140 g) was subjected to potassium permanganate oxidation (22).…”

“…The resulting aldehydes were extracted with chloroform, reduced with lithium aluminum hydride, and separated into two aliquots; one (200 g) was used to produce the nicotinates (22), and the other (140 g) was subjected to potassium permanganate oxidation (22). The resulting fatty acids were transformed to methyl esters by etheral diazomethane.…”

Periodate–permanganate Oxidations: I. Oxidation of Olefins

“…These results were probably due t o the ability of permanganate t o catalyze autoxidation (15). After it was shaken for 18 hr., the solution, pH 7.6, was analyzed as described above for oxidant content and for formaldehyde (7). Since the consumption of oxidant equivalent t o 0.402 milliatoms of oxygen resulted in the formation of only 0.11 mM.…”

Rapid quantification of total microcystins in cyanobacterial samples by periodate-permanganate oxidation and reversed-phase liquid chromatography

“…This method is believed to be an accurate method for screening for total MCs because it can measure MMPB derived from the unusual C 20 amino acid, ␤-amino acid (2S, 3S, 8S, 9S)-3-amino-9-methoxy-2, 6, 8-trimethyl-10-phenyldeca-4, 6-dienoic acid (Adda), which is a common constituent moiety of MCs [7]. Oxidizing toxins using the Lemieux oxidation method [33][34][35][36][37] have been widely used as a highly sensitive method for the detection of total MCs in a wide range of sample matrices, including cyanobacteria [38,39], animal tissues [40][41][42][43][44] and serum samples [45][46][47]. However, no studies have been conducted to evaluate the influence of reaction conditions on the formation of MMPB during the oxidation of MCs using permanganate-periodate.…”