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 1H and 13C NMR spectral assignment of the mono-, di- and triacetates.
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 1H and 13C NMR techniques were used in the structure elucidation and assignment of the different NMR resonances of these three acetylated compounds.
Martins
F J C
FJ
Department of Chemistry, Potchefstroom University for CHE, Potchefstroom 2520, South Africa. cheamu@puknet.puk.ac.za
Viljoen
A M
AM
Kruger
H G
HG
Wessels
P L
PL
D000085:Acetates / Q000032:analysis* / Q000737:chemistry*; D000473:Alkanes / Q000032:analysis* / Q000737:chemistry*; D002247:Carbon Isotopes; D003461:Crystallography / Q000379:methods*; D007769:Lactams / Q000032:analysis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008968:Molecular Conformation; D011522:Protons
D000085:Acetates; D000473:Alkanes; D002247:Carbon Isotopes; D007769:Lactams; D011522:Protons; C022884:undecane