Synthesis of derivatives of the new condensed system 4H,7H-furo[3′,4′:6,7]cyclohepta[1,2-b]pyran
摘要:
8-Hydroxy-1,3-dimethyl-4H-cyclohepta[c]furan-4-one reacts with arylidenemalononitriles and, like 1,3-oxo enols, forms the corresponding condensed 2-amino-4H-pyrans. The analogous reaction with 3-(dicyanomethylene)indolin-2-ones give spirocyclic 2-amino-4H-pyrans. The 4-aminopyrimidine ring is formed on the basis of the enamino nitrile fragment of the new pyrans by successive reaction with triethoxymethane and then with aqueous ammonia.