Structure elucidation of 11‐amino‐8‐hydroxypentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ]undecane‐8,11‐lactam through selective acetylation and complete 1 H and 13 C NMR spectral assignment of the mono‐, di‐ and triacetates

• Published in: Magnetic resonance in chemistry 2004-04, Vol.42 (4), p.402-408
• Main Authors: Martins, F. J. C., Viljoen, A. M., Kruger, H. G., Wessels, P. L.
• Format: Article
• Language: English
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.1355

NMR techniques cannot unambiguously distinguish between 11‐amino‐8‐hydroxypentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ]undecane‐8,11‐lactam and 8‐amino‐11‐hydroxypentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ]undecane‐8,11‐lactam, both of which are possible products during the reaction of pentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ]undecane‐8,11‐dione with Strecker reagents. Treatment of 11‐amino‐8‐hydroxy‐pentacyclo[5.4.0.0 2, 6 .0 3, 10 .0 5, 9 ]undecane‐8,11‐lactam with acetic anhydride at room temperature produced a monoacetate. With acetic anhydride containing sodium acetate, a triacetate was obtained at reflux temperature. Treatment with acetyl chloride and N , N ‐dimethylaniline produced a diacetate. High‐field 1 H and 13 C NMR techniques were used in the structure elucidation and assignment of the different NMR resonances of these three acetylated compounds. Copyright © 2004 John Wiley & Sons, Ltd.