61936-09-2Relevant articles and documents
STEREOCHEMICAL STUDIES, 144. SATURATED HETEROCYCLES, 151. PREPARATION OF cis AND trans-CYCLOALKANE-CONDENSED PYRIMIDINEDIONES BY AZETIDINONE RING TRANSFORMATION
Stajer, Geza,Szoeke-Molnar, Zsolt,Bernath, Gabor,Sohar, Pal
, p. 1943 - 1950 (2007/10/02)
N-substituted derivatives (3 and 4) obtained from cyclopentane- and cyclohexane-azetidinones (1 and 2) were isomerized with polyphosphoric acid to give cyclopentane-cis- (6) and cyclohexane-trans-condensed (7) 2,4-pyrimidinediones.The structures of the dihydrouracils prepared by the ring transformation were proved by 1H- and 13C-nmr spectroscopy and by comparison with the compounds synthesized from cis- and trans-2-amino-1-cycloalkanecarboxamides (11-13) with 1,1'-carbonyldiimidazole.