Naslov
Chemistry of 1,3-dioxepines. XIII. (E)/(Z) Configurational assignment of 4,7-dihydro-4- hydroxyimino-6-nitro-1,3-dioxepins

Autori
Jadrijević-Mladar Takač, Milena ; Butula, Ivan ; Vikić-Topić, Dražen ; Dumić, Miljenko

Izvornik
Croatica chemica acta (0011-1643) 71 (1998), 3; 557-571

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
1;3-Dioxepins; 4;7-dihydro-4-hydroxyimino-6-nitro-1;3-dioxepins; (E)/(Z) configurational assignment; 1D and 2D NMR spectra; 1H and 13C NMR correlated spectra; differential NOE

Sažetak
The configuration of oximes 1a and 1b was investigated by chemical and spectroscopic methods. Under the Beckmann rearrangement conditions, using sulfonyl chlorides as reagent, the sulfonic esters 2a-c were obtained. Under more drastic condition, using PCl5 or P2O5, the only isolated product was 4-nitro-5H-furan-2-on (3). It was also formed as sole product by hydrolysis of oximes 1a-b, as well as sulfonic ester 2a. The structure of all compounds were determined by one- and two-dimensional homo- and heteronuclear 1H and 13C NMR correlation spectra: COSY, NOESY, HETCOR and HMBC. Gradient selected differential NOE measurements confirmed that in dimethylsulfoxide solution oximes 1a and 1b exist in E-configuration, irrespective of the route of their formation.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA