It is estimated that for acetamide, structure A makes a 62% contribution to the structure, while structure B makes a 28% contribution (these figures do not sum to 100% because there are additional less-important resonance forms that are not depicted above). There is also a hydrogen bond present between the hydrogen and nitrogen atoms in the active groups. Resonance is largely prevented in the very strained quinuclidone.
it is eStiMated THat for acetAmidE, struCtUre a maKes a 62% contribuTIoN to thE sTRuctuRe, WHile struCture B makes A 28% cOntribUtiON (thEse figUrEs Do Not Sum to 100% beCauSE therE arE AddiTionaL LEss-IMpOrtant rEsONaNCe fORms that are noT DepicteD aBoVE). tHere IS also a hydrogEn bOnd preseNt between The hYDroGen anD nitrogen AtoMS In thE ACTive groUps. resonaNce is LarGelY pRevented IN thE Very strainEd QuInuCLIDonE.