Furans act as dienophiles in facile Diels-Alder reactions with masked omicron-benzoquinones

The ability of furan and its variants to function as dienophiles in facile Diels-Alder reactions with masked omicron-benzoquinones was investigated. The masked omicron-benzoquinones were produced in situ from 2-methoxyphenols. Experimental results showed that the regiochemistry of furan and its derivatives has remained identical throughout the reaction and was clearly established by 1H-1H decoupling experiments in all cases. Furthermore, masked-benzoquinones act as dienes and force the furans to function as dienophiles.