ABSTRACT: The Claisen rearrangement of 4-propargyloxycoumarins affords 2H-,5H-pyrano[ 3,2-c][I]benzopyrans-5-ones as the only product.. The effect of solvent. on the Claisen rearrangement. has been examined. ... As a part of investigations on the use of Claisen rearrangement. in ... 4-Hydroxycoumkarins (la-d5 were propargylated by refluxing with ... 4.85 1.2.2 4.90 J.2.5 4.98 1.2.0 4.83 J.2.5 4.85 J.2.0 ... 7.16-7.62 m,3H 7.1 3-7.53 m,2H 7.1 2- ...