The molybdenum-mediated cleavage reactions of isoxazoline rings fused in bicyclic frameworks were investigated. A tandem N-O bond cleavage-retro aldol reaction of an isoxazoline ring fused in a bicyclic framework led to the cleavage of the bicyclic framework. These reactions provide a novel stereoselective synthesis of substituted cyclopentene rings, cyclopentane rings, and attached-ring system...

Isoxazoline γ-lactams are prepared starting from the regioisomeric cycloadducts of benzonitrile oxide to the N-alkyl 2-azanorbornenes taking advantage of the efficient catalytic oxidation by RuO(4). The reduction of the amide groups is easily conducted in the presence of LiAlH(4) under mild conditions, which allowed for the chemoselective reduction of the amide moiety followed by ring opening t...

Different novel isoxazolines were synthesized by the cyclization of secondary amino derivatives with pyridazine as a substituted intermediate in presence hydroxylamine hydrochloride. Isoxazoline is an important class nitrogen and oxygen-containing five-membered heterocyclic compounds having great medicinal importance. Many heterocyclic, pharmaceutically active have been using it intermediate. D...

The title compound, C(25)H(20)N(2)O(4), is a new spiro-isoxazoline derivative. It contains a five-membered isoxazoline ring (A), a tetra-lone unit (E and D), a 4-nitro-phenyl substituent (B), and a phenyl ring (C). The isoxazoline ring (A) has an envelope conformation, while the cyclo-hexenone ring (D) has an inter-mediate sofa/half-chair conformation. The aromatic ring of the 4-nitro-phenyl su...

A series of carbapenems containing novel C-2 semisaturated heterocyclic substituents were synthesised by 1,3 dipolar cycloaddition reactions of nitrile oxides, nitrile imines and a nitrone to 2-vinylcarbapenem. The isoxazoline and isoxazolidine compounds showed potent antibacterial activity but moderate stability to human dehydropeptidase 1 (DHP-1). Stability to DHP-1 was improved by methyl sub...

In the present investigation, a series of novel isoxazoline derivatives 4a-i were synthesized by cyclization of 1-(2’-hydroxy phenyl)-5-(6’’-methoxynaphthalen)-2-propene-1-one (i.e. Chalcones) 3a-i with hydroxylamine hydrochloride in dimethyl formamide and sodium acetate to obtained 3-(2’-hydroxy phenyl)-5-(6’’-methoxynaphthalen)-2-isoxazolines 4a-i. The structures of newly synthesized compound...

In the title compound, C(15)H(12)ClNO, the isoxazoline ring adopts an envelope conformation with the C atom bearing an unsubstituted phenyl ring as the flap atom. The chlorinated phenyl group is nearly in-plane with the four coplanar atoms of the heterocycle and the corresponding mean planes enclosing an angle of 1.16 (7)°. The unsubstituted phenyl group attached to the envelope flap atom appro...

New peptidomimetics containing a β2,2-isoxazoline amino acid, 5-(aminomethyl)-3-phenyl-4,5-dihydroisoxazole-5-carboxylic acid (Isox-β2,2AA), were prepared and studied by NMR theoretical calculations. Interestingly, inserting R-Isox-β2,2AA in short tri- hexapeptide models, an unexpected α-turn-like motif was observed, thanks to unprecedented strong H-bond involving C=N of isoxazoline side chain ...