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.
Asymmetric Organocatalytic Synthesis of Substituted Chiral 1,4-Dihydropyridine Derivatives
作者:Fernando Auria-Luna、Eugenia Marqués-López、M. Concepción Gimeno、Roghayeh Heiran、Somayeh Mohammadi、Raquel P. Herrera
DOI:10.1021/acs.joc.7b00176
日期:2017.6.2
anocatalyzed enantioselective synthesis of chiral 1,4-dihydropyridine derivatives is described. Bis-cinchona catalyst 3b activates the Michael addition reaction between malononitrile derivatives 2 and enamines 1, affording the appealing and highly substituted 1,4-dihydropyridines 4 with very good results in most cases. This is one of very few examples of the synthesis of chiral 1,4-dihydropyridines