O-Ethylvalerolactonium Tetrafluoroborate and Valerolactone Diethylacetal in the Synthesis of Condensed Pyrans

Article abstract of DOI:10.1007/BF00505749

A pyrano<2,3-b>quinoline derivatives was obtained by the reaction of O-ethylvalerolactonium tetrafluoroborate with ethyl anthranilate and subsequent cyclization of the intermediate imido ester.A number of derivatives of pyrano<2,3-c>pyridine and pyrano<2,3-d>pyrimidine derivatives were synthesized on the basis of valerolactone diethylacetal and α-dimethylaminomethylenevalerolactone diethylacetal.