Synthesis of azuleno [1, 2-b]-and azuleno [1, 2-c] thiophenes by the reactions of 2H-cyclohepta [b] furan-2-ones with enamines of 3-oxotetrahydrothiophenes

~82%

~%

~%

~65%

~%

~99%

~%

~%

~%

~23%

~42%

~55%

~76%

~%

~%

~72%