13C n.m.r. studies. IX. Carbonyl carbon shieldings of some cyclopropyl ketones

• Published in: Canadian journal of chemistry 1967-02, Vol.45 (3), p.225-231
• Main Authors: Marr, D. H, Stothers, J. B
• Format: Article
• Language: eng ; jpn
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v67-044

The 15.1 Mc/s 13 C nuclear magnetic resonance spectra of 15 aliphatic and alicyclic ketones having a three-membered ring alpha to the carbonyl group have been obtained and the shieldings of their carbonyl carbon nuclei are reported. A number of derivatives of bicyclo-[4.1.0]heptan-2-one, bicyclo[3.1.0]hexan-2-one, spiro[2.5]octan-4-one, and spiro[2.4]heptan-4-one have been included. The primary objective was to investigate the question of conjugation of the cyclopropyl ring with a carbonyl grouping, since we had shown previously that 13 C shieldings of carbonyl carbons are significantly affected by conjugative interactions. The 13 C data for several related compounds were obtained to aid in our assessment of the cyclopropyl results. Some evidence of cyclopropyl conjugation is presented.