Preparation of a series of terminally and internally substituted delta-alkenyl and delta-alkynyl esters 6, 7 and 9, potential precursors to oxazin-2-one nitrones, has been attempted. Condensation between pyruvic or benzoylformic acid and the appropriate alcohol proceeded smoothly in some cases whilst allylic transposition was a major feature in other cases--most especially during reactions with...

2-Isoxazolines represent a well known class of heterocycles, readily accessible in particular by 1,3-dipolar cycloaddition of nitrile oxides to alkenes. 2-Isoxazolines are easily transformed into 2isoxazolinium salts by N-methylation, and further into 3-isoxazolines by deprotonation. In contrast to the parent system, less is known concerning the chemistry of the derived classes, and potential a...

2-(Pyrrol-1-yl)phenoxyl, aminyl, thiophenoxyl and benzyl radicals 2a-2d, respectively, were generated in the gas-phase under flash vacuum pyrolysis conditions. In all cases except the phenoxyl, cyclisation took place providing acceptable synthetic routes to the fused heterocycles 11, 14 and 15, respectively. Only sigmatropic rearrangement products were isolated, in low yields, from the phenoxyl...

Recently, it was reported that both dienylfurans and dienylisobenzofurans could react with dimethyl acetylenedicarboxylate (DMAD) to give [8+2] cycloadducts. Understanding these [8+2] reactions will aid the design of additional [8+2] reactions, which have the potential for the synthesis of 10-membered and larger carbocycles. The present Article is aimed to understand the detailed mechanisms of ...

Dimethyl (z)-2-[(2-methyl-5-oxo-1-cyclopentyl)oxy]-2-butenedioate has been synthesized using one-pot three component reaction between N-isocyaniminotriphenylphosphorane (Ph3PNNC), 3-methylcyclopentene-1,2-dione and dimethyl acetylenedicarboxylate. Also, optimized geometry and nuclear magnetic resonance ( NMR ) of the title compound are evaluated using HF and B3LYP methods and 6-311+G(d) basis s...

Derivatives of thiazolidinone ring systems are known to act as anti-HIV infections , analgesic, anti-bacterial, anti-convulsant, anti parasitic, potential anti-inflammatory and herbicidal agents. Due biological activities of thiazolidinones ring, several methods for their synthesis have been illustrated in literature. Imidazolidine-2-thiones were synthesized by the oxidative cyclization of 1-be...

an efficient synthesis of methyl 2-[2-(alkylimino)-4-oxo-3-phenyl-1,3-thiazolan-5-yliden]acetate derivatives via simple three-component reaction and one-pot reactions between isoquinoline, dimethyl acetylenedicarboxylate and n-phenylthiourea under solvent-free conditions without using any additional catalyst, is described. the mild reaction conditions and good yields and exhibit the synthetic a...

The thermal reaction of trans-1-methyl-2,3-diphenylaziridine (trans-1a) with aromatic and cycloaliphatic thioketones 2 in boiling toluene yielded the corresponding cis-2,4-diphenyl-1,3-thiazolidines cis4 via conrotatory ring opening of trans-1a and a concerted [2þ 3]-cycloaddition of the intermediate (E,E)-configured azomethine ylide 3a (Scheme 1). The analogous reaction of cis-1a with dimethyl...