CLAISEN REARRANGEMENT OF 4-ALLYLOXY-l-p-METHOXY-BENZYLPYRAZOLE AND SYNTHESIS OF PYRAZOLE-FUSED 7-MEMBERED LACTONES

摘要

Allyl 4-pyrazolyl ethers were subjected to the Claisen rearrangement that involved heating under microwave condition to prepare the corresponding products with regioselective allylation at 5-position of the pyrazoles in good yields.The rearrangement products were converted into 7-membered pyrazololactones having an oxygen atom at 4-position of pyrazole,via a hydroesterification reaction with Pd(OAc)2 and DPE-phos as ligand under 40 atm of CO/H2（6:34)in moderate to excellent yields.