Microwave-Assisted Mild Conversion of Natural Dihydrotagetone into 5-Isobutyl-3-methyl-4,5-dihydro-2(3H)-furanone, an Analogue of Whisky Lactone

Abstract

A microwave-assisted mild protocol is developed for the synthesis of 5-isobutyl-3-methyl-4,5-dihydro-2(3H)-furanone, an analogue of whisky lactone, from dihydrotagetone, an acyclic monoterpenoid obtained from Tagetes minuta. The methodology involved oxidation of dihydrotagetone in the presence of sodium metaperiodate/potassium permanganate/alumina to give 2,6-dimethyl-4-oxo-heptanoic acid, which upon reduction and subsequent lactonization provided 5-isobutyl-3methyl-4,5-dihydro-2(3H)-furanone. The reaction is also conducted under conventional conditions and is compared with the microwave method.

Ultrasound‐enhanced Green Synthesis of 5,5‐Diphenylhydantoin Derivatives Using Symmetrical or Unsymmetrical Benzils

“…The notable features of the ultrasound approach are enhanced reaction rates, formation of pure products in high yields, easy manipulation and considered processing aid in terms of energy conservation and waste minimization compared with traditional methods and this technique is more convenient to take green chemistry concepts into accounts. [14][15][16] In this work, we wish to report a rapid and efficient synthesis of 5,5-diphenylhydantoins using ultrasound irradiation.…”

Phase Transfer Ceria-Supported Nanocatalyst for Nitrile Hydration Reaction

“…Currently, PTC is an ingenious process, which is also environmentally benign. The reaction mechanism indicates that the reaction pathway proceeds through the formation of hydroxyl ions over the “Ce”-supported catalyst, to enhance the formation of such reactive ions and several organic reactions both microwave irradiation and ultrasound used. ,− High temperature and local pressure are induced with ultrasonic waves to increase the mass transfer and flow of the reactants, and this helps in reducing the reaction time and increase the yield…”

Aldol condensations of a variety of different aldehydes and ketones under ultrasonic irradiation using poly(N-vinylimidazole) as a new heterogeneous base catalyst under solvent-free conditions in a liquid-solid system

“…There are several notable features to UAOS, including enhanced reaction rates, improved levels of selectivity, higher product yields and purity, and facile manipulation. Furthermore, UAOS can be considered as a processing aid in terms of energy conservation and waste minimization compared with traditional methods, and represents a chemistry platform that is much more amenable to the implementation of green chemistry concepts [8][9][10][11][12][13][14]. We recently described a series of different syntheses that were catalyzed by new solid acid catalysts under ultrasound irradiation conditions, including the synthesis of 14-aryl-14H-dibenzo [a,j]xanthenes [15], a one-pot synthesis of substituted coumarins [16], and the chemoselective 1,1-diacetate protection and deprotection of aldehydes [17].…”