| Abstract: | A convenient and simple method for the synthesis of novel 3,4‐dihydrofuran‐annulated coumarins, 3‐(hydroxymethyl)‐2H‐furo[3,2‐c]chromen‐4(3H)‐ones 5a , 5b , 5c , 5d , 5e , 5f , 5g , by combined Claisen rearrangement and intramolecular regioselective oxidative cyclization of 4‐O‐allyl coumarin intermediates 3a , 3b , 3c , 3d , 3e , 3f , 3g using inexpensive oxidizing agent m‐CPBA is described. The reaction proceeds smoothly by tandem epoxidation/regioselective 5‐exo‐tet‐intramolecular ring opening. The structures of synthesized compounds are established on the basis of spectral data including IR, 1H NMR, and mass and elemental analyses. |
