A Versatile Synthetic Method of 1-Alkylazulenes and Azulene by the Reactions of 3-Methoxycarbonyl-2H-cyclohepta[b]furan-2-one within situGenerated Enamines
A Versatile Synthetic Method of 1-Alkylazulenes and Azulene by the Reactions of 3-Methoxycarbonyl-2H-cyclohepta[b]furan-2-one within situGenerated Enamines
A Versatile Synthetic Method of 1-Alkylazulenes and Azulene by the Reactions of 3-Methoxycarbonyl-2<i>H</i>-cyclohepta[<i>b</i>]furan-2-one with<i>in situ</i>Generated Enamines
Methyl 3-alkylazulene-1-carboxylates were synthesized in high yields by the reaction of 3-methoxycarbonyl-2H-cyclohepta[b]furan-2-one with in situ generated morpholine enamines of aldehydes. Treatment of the esters with 100% phosphoric acid gave 1-alkylazulenes in excellent yields. Azulene was also synthesized in a good yield via methyl azulene-1-carboxylate with a modification of this method.