Intramolecular Diels-Alder reaction of furans with allenyl ethers followed by phenylthio and trialkylsilyl groups rearrangement

Abstract

a new reaction involving an intramolecular Diels-Alder reaction of a furan diene with an allenyl ether dienophile followed by phenylthio group rearrangement was discovered. Treatment of the propargyl ethers 2a-c with t-BuOK in t-BuOH at 85 degrees C gave the phenylthio group rearrangement products 5a-c and 6a-c. A reaction involving an intramolecular Diels-Alder reaction of a furan diene with an allenyl ether dienophile followed by trialkylsilyl group rearrangement is also demonstrated.