3‐[( Z )‐2‐ t ‐Butoxyethenyl]‐4‐hydroxy‐2(5 H )‐furanone, an interesting byproduct obtained from reaction of 4‐ t ‐butoxy‐2‐butenoate with the alkoxide anion of methyl glycolate

Treatment of methyl 4‐ t ‐butoxy‐2‐butenoate ( 1 ) with the alkoxide anion of methyl glycolate gives, in addition to the previously reported (Fried, et al . [2]) 2,3‐disubstítuted‐2,3‐dihydro‐4‐furanone 2 , an equivalent amount of the interestingly substituted 3‐[( Z )‐2‐ t ‐butoxyethenyl]‐4‐hydroxy‐2(5 H )furanone 3 . Isolation, structure proof and possible mechanism of formation are presented