Producción Científica Profesorado

Conformational studies on indole alkaloids from Flustra foliacea by NMR and molecular modeling



Suárez Castillo, Oscar Rodolfo

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.



Producto de Investigación




Artículos relacionados

The absoluteconfiguration of cuauhtemone and related compounds

Reactivity of TpMe2Ir(C2H4)(DMAD) with carboxylic acids. A DFT study on geometrical isomers and stru...

Trapping enols of esters and lactones with diazomethane

Conformationalstudies of N-carbomethoxy-2-alkoxyindolenines by dynamic NMR, crystallography, and mol...

Synthesis of 6-bromo-2-arylindoles using 2-iodobenzoic acid as precursor

Absolute configuration determination of 2-(2-oxo-3-indolyl)acetamide derivatives

Role of lipid peroxidation in biliary obstruction in the rat

Synthesis of ?4:?2-Exocyclic-Diene Iridium(I) Complexes Derived from 1,3-Oxazolidin-2-ones and Their...

Synthesis of Bromoindole Alkaloids from Laurencia brongniartii

Configuration, stereodynamics and crystal structure of 3-substituted-2-oxofuro[2,3-b]indoles