Conformational Studies of (±)-11,12-Didehydro-11-deoxycorynoline and (+)-11,13-Didehydro-11-deoxychelidonine, Hexahydrobenzo[c]phenanthridine-Type Alkaloid Derivatives, by X-Ray Crystal Structure and NMR Analyses

摘要

The X-ray crystal analyses of the two 11-deoxy-didehydrohexahydrobenzo[c]phenanthridine-type alkaloid derivatives 3 and 4, derived from (±)-corynoline (1) and (+)-chelidonine (2), established their structures as (±)-(5bRS,12bRS)-5b,12b,13,14-tetrahydro-5b,13-dimethyl[1,3]benzodioxolo[5,6-c]-1,3-dioxolo[4,5-i]phenanthridine (3) and (+)-rel-(12bR)-7,12b,13,14-tetrahydro-13-methyl[1,3]benzodioxolo[5,6-c]-1,3-dioxolo[4,5-i]phenanthridine (4). The conformations of 3 and 4 in CDCl₃ were determined on the basis of 1H- and 13C-NMR spectroscopy.