NMR Studies on 1,3-Dipolar Cycloaddition of Nitrile Oxides to Norbornenes

NMR Studies on [2 + 3] Cycloaddition of Nitrile Oxides to Polyunsaturated Medium Size Rings

“…Some discrepancy from this regularity was noticed for b-humulene (8), where the bis-adduct 9 was formed in reaction of the most electron-rich C8-C12 bond and the least electron rich C1-C2 double bond. It could be explained by the steric factors and a more difficult approach of the dipole to the hindered internal double bond of the dipolarophile flanked with two geminal methyl groups.…”

“…7 Similarly, in recently examined cycloadditions of aryl nitrile oxides to norbornenes substituted with an acrylate-derived moiety, only adducts to norbornene system were formed with good site and exo selectivity. 8 Site selectivity and regioselectivity of cycloaddition to cyclohexene derivatives was studied in our group. 9 2,6-Dichlorobenzonitrile oxide reacts with isothiazolones at the ethylenic double bond.…”

The influence of the structure of various isoxazole derivatives on photosynthetic apparatus of tomato plants grown in the field and greenhouse. Effect of various stages of plant growth in different seasons

“…2-isoxazolinecarboxylic acid chlorides were prepared by the published procedures from the corresponding aldehydes, cf. Scheme 1 (Gucma, Gołębiewski, & Krawczyk, 2013;Gucma, Gołębiewski, & Michalczyk, 2016).…”

“…prop-2-enoate 12 (Gucma et al, 2013), and a cycloadduct of 4-trifluoromethylbenzonitrile oxide to sesquiterpene C 15 trans, trans, trans-2,6,6,9-tetramethyl-1,4,8-cycloundecatriene 13 (Gucma et al, 2016). Probably isoxazole 27 inhibited the electron transport in these leaves.…”

Studies on the [2+3] cycloaddition reaction of nitrile oxides to abietic acid esters

“…Cycloadditions of aryl nitrile oxides to alkene-substituted norbornene derivatives were characterized by a high degree of site-selectivity and only the double bond of the norbornene system participated in the reactions. 13,14 On the other hand, in the reaction of polyunsaturated cholecalciferol acetate, only adducts to the exocyclic double bond were formed. 15 Copper-catalyzed [2+3] dipolar cycloaddition of abietic acid propargyl ester derivatives with azides afforded quaternary ammonium compounds exhibiting strong antibacterial and antibiofilm activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli.…”