Synthesis in Coumarino-pyrone and Furocoumarin Groups, Part I. Synthesis of 4,2'-Diznethyl-6-ethylconmarino-7,8-γ-pyrone and 4,4'-Dimethyl-6-ethylcouniarino-7,8,α-pyrone

The Kostanecki acylation of 4-methyl-6-ethyl-8-acetylumbelliferone furnishes two compounds: (A) C₁₈H₁₆O₃. m.p. 198°, and (B) C₁₆H₁₄O₄. m.p. 335^°. Compound (A) on hydrolysis with caustic alkali furnishes (i) an acid, C₁₃H₁₅O₅, m.p. 240°, and (ii) a neutral compound, C₁₆,H₁₄O₄, m.p. 203^°.

From chemical evidences compound (A) has boon proved to be 4,2'-dimethyl 3'-acetyl-6-ethylconmarino­7,8- 7-pyrone and its deaoetylated product, 4,2'-dimethyl-6-ethylcomnarino-7,8-γ-pyrone.

The product (B), m.p. 335°, has been similarly proved to be isomeric with the coumarino-γ-pyrone (II), m.p. 203°, and is represented as 4,4'-dimethy1-6-ethylcoumarino-7, 8- α-pyrone.