Convenient synthesis of angular pyranocoumarin from hydroxycoumarin and 1, 1-diethoxy-3-methyl-2-butene according to the North's method was investigated. Both 5- and 7-hydroxycoumarins afforded corresponding pyranocoumarins in a comparatively good yield. Moreover, effects of additives and solvents were examined, and in the presence of cesium fluoride (CsF) in diethylaniline, 6-hydroxycoumarin provided the corresponding pyranocoumarin in a 62% yield.