Interconvertions between delta-lactam and delta-lactone derivatives initiated by unique transannular interactions of the rigid cyclohexane boat structure in pentacycloundecane.
The pentacycloundecane (PCU) cage structure resembles a perfect boat conformation, and for the first time unique lactam/lactone interconversions on the flagpole carbons of a cyclohexane boat structure are reported. The syntheses of a novel dihydroxy-PCU-delta-lactone and two novel N-substituted PCU-delta-lactams are reported. Hydrolysis of some of the PCU-delta-lactam compounds produced delta-lactones, and reaction of the lactones with ammonia or primary amines again produced delta-lactams. Reaction mechanisms to account for the unusual interconversion reactions induced by transannular interactions are proposed.
Kruger
Hendrik G
HG
School of Chemistry, University of Kwazulu-Natal, Durban 4001, South Africa.
Martins
Frans J C
FJ
Viljoen
Agatha M
AM
D002384:Catalysis; D003510:Cyclohexanes / Q000737:chemistry*; D007769:Lactams / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism
D003510:Cyclohexanes; D007769:Lactams; D007783:Lactones