Synthesis of di- and cis -triaryl-3a,4,5,6-tetrahydroimidazo[1,5- b ]isoxazoles and their ring-opening reactions

Synthesis and Ring Opening Reactions of Tetrahydroimidazo[1,5- b ][1,2,4]oxadiazol-2(1 H )-thiones

“…Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. 7 We have shown the 1,3-dipolar cycloaddition reactions of cyclic nitrones 1 with dipolarophiles as arylisocyanates, 8,9 styrene, 10 DMAD, 11,12 and β-pinene 13 to proceed regio and in the case of chiral nitrones diastereoselectively. 1 1,3-Dipolar cycloadditions of nitrones with variety of dipolarophiles take an important place among the methods for the synthesis of five membered heterocyclic compounds.…”

The chemistry of 2,3-dihydroisoxazole derivatives

“…[32][33][34][35] Other characteristic transformations are ring opening reac tions usually involving cleavage of the N-O bond. 6 Below we consider some examples of reactions of 2,3 di hydroisoxazoles with retention of the heterocycle: (1) ad dition to the double bond leading to isoxazolidine de rivatives and (2) elimination reactions giving rise to a new double bond (in this case, isoxazoles are reaction products).…”

“…32, 33 If the double bond bears electron withdraw ing substituents, base catalyzed nucleophilic addition is also possible. 35 Examples are shown in Scheme 7.…”

4‐Isoxazolines: Scaffolds for Organic Synthesis

“…[78,79] On the other hand, diastereoselective rearrangement of 199 in the presence of methoxide gives the tetrahydro-1H-pyrrolo[1,2-c]imidazole-6-olates 201. Acidic hydrolysis of these heterocycles followed by intramolecular transformylation affords the 2,5-dihydro-1H-pyrrole derivatives 203.…”