Relative acidities and structure analysis of cis and trans isomers of 1,5-oxazaspiro[5.5] undecane derivatives by multinuclear magnetic resonance

Jorge Antonio Guerrero-Alvarez; Wendy Paloma Mas-Ku; Cesar Garcías-Morales; Armando Ariza-Castolo

doi:10.1002/mrc.2592

Relative acidities and structure analysis of cis and trans isomers of 1,5-oxazaspiro[5.5] undecane derivatives by multinuclear magnetic resonance

Magn Reson Chem. 2010 May;48(5):356-61. doi: 10.1002/mrc.2592.

Authors

Jorge Antonio Guerrero-Alvarez¹, Wendy Paloma Mas-Ku, Cesar Garcías-Morales, Armando Ariza-Castolo

Affiliation

¹ Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Av. Universidad No. 1001, Col. Chamilpa, Cuernavaca Morelos 62210, Mexico. jguerrero@ciq.uaem.mx

PMID: 20306516
DOI: 10.1002/mrc.2592

Abstract

The relative acidities of the cis and trans isomers of a series of 1,5-oxazaspiro[5.5]undecane derivatives were determined by measuring DeltapK in acid-base titrations followed by (1)H NMR. Relative structural stabilities were determined by measuring substituent chemical shift and gamma-gauche effects in (13)C, (15)N, and (17)O NMR. Crystallographic characterization of a model spiro[5.5]undecane is presented to support the basicity in solid state.