On the curious oxidations of 2-furylethanols

Rather than giving the corresponding aldehyde or carboxylic acid, Jones oxidation of 5-substituted-2-furylethanols gives rise to high yields of the corresponding dihydro-2-(2-oxoethyl)furan-3(2H)-ones, following Achmatowicz-type oxidative ring opening and subsequent reclosure by a 5-exo Michael addition of the pendant hydroxy group to the enedione function. Other oxidation methods such as a Swern reaction give lower yields of the same products while magnesium perphthalate tends to yield the intermediate enediones, and IBX tends to yield the furyl aldehydes.