Chemistry of acetylenic ethers XXXIII: The addition of ethoxyethyne to diphenylketene

Abstract

Abstract Ethoxyethyne reacts easily with diphenylketene. I. The nature of the product depends upon the reaction temperature and the solvent. In benzene at room temperature, a 34% yield of 1‐phenyl‐2‐ethoxy‐4‐hydroxynaphthalene, VI, is obtained, whereas in nitromethane at −20° the product is 1,1‐diphenyl‐2‐ethoxy cyclo but‐2‐ene‐4‐one. XXX. These structures have been proved by several reactions and by synthesis of degradation products. Similar reactions have been performed between 1‐ethoxy‐1‐propyne (XXXIV, R = C 2 H 5 ), 1‐methoxy‐1‐propyne (XXXIV, R = CH 3 ) and diphenylketene, I, yielding again a cyclo butenone, XXXV, and a naphthol, XXXVI.