Chromatographie en phase gazeuse et lipochimie

Challenging cyclopropanation reactions on non-activated double bonds of fatty esters

“…When EDA was slowly added during 10 h, the same maximum yield was obtained at shorter reaction time (entry 8). Considering the importance of EDA dimerization, the amount of diazocompound was increased (entries [9][10][11], and quantitative yield of cyclopropanes 2 + 3 was obtained with an EDA/oleate molar ratio of 3.…”

“…Only in one case unsaturated fatty esters were made react with diazomethane in a Pd catalyzed cyclopropanation, 8 whereas one single example was described for the copper catalyzed cyclopropanation with ethyl diazoacetate 9 and another one using diazoketones. 10 In fact, the resulting difunctional compounds of the latter reactions may open the way to further modications for different uses. However, the articles describing the preparation of these functionalised cyclopropanes 9,10 were published 50 years ago and hence both the methods for determination of results and, specially, the characterization of the products were limited or very decient.…”

Azoxy Compounds

“…Under the reaction conditions, /?-toluidine was converted only into/7-nitrotoluene [31]. The reaction did not pass through the azo stage of oxidation since azo compounds could not be converted under the reaction conditions and hydrazo compounds were oxidized to azo compounds.…”

“…[31] O A stirred mixture of 0.615 gm (5 mmoles) of /?-anisidine (freshly recrystallized from carefully deionized water) in 50 ml of petroleum ether is cooled in an ice bath and maintained between 5°C and 7°C throughout the reaction. Metal stirring rods must be avoided.…”

Azo Compounds

“…It has now been demonstrated that simple oxidation of aromatic amines with peracids produces azoxy compounds without the intermediate formation of azo compounds [71]. It has now been demonstrated that simple oxidation of aromatic amines with peracids produces azoxy compounds without the intermediate formation of azo compounds [71].…”