2002
Conformational studies on indole alkaloids from Flustra foliacea by NMR and molecular modeling. Morales-Ríos Martha S., Santos-Sánchez Norma F., Suárez-Castillo Oscar R. DOI: 10.1002/mrc.1080
Abstract
1H and 13C NMR assignments for 1a4a and 1b4b were obtained using HSQC, HMBC and NOESY techniques. Differences and ambiguities from literature assignments are reconciled. For the pyrrolidine C-ring, the combined use of NMR spectroscopy and molecular mechanics calculations revealed that this ring exists in a dynamic conformational equilibrium between twist (2T1) and envelope-twist (1E1T2) conformations. In chloroform-d1, the 1H NMR coupling constants indicate that the pyrrolidine ring is biased in favor of the envelope-twist conformation. Steric requirements of the N-prenyl group enhanced the envelope-twist (1E1T2) conformation populations.
Unimolecular rearrangements of ketene-O,O-acetals and fragmentations occurring in the gas phase
Synthesis of 6-bromo-2-arylindoles using 2-iodobenzoic acid as precursor
13C NMR and crystallographic evidence of push-pull effects in furoindolic ?-enamino esters
Regioselective Synthesis of 3-Indolyl(alkoxy)acetates
Synthesis of Bromoindole Alkaloids from Laurencia brongniartii
Cleavage of alkoxycarbonyl protecting groups from carbamates by t-BuNH2
Trapping enols of esters and lactones with diazomethane
Absolute configuration determination of 2-(2-oxo-3-indolyl)acetamide derivatives