obsolete 4-hydroxy-5-methyl-2-propyl-3(2H)-furanone oxidoreductase activity (obsolete GO:0102981)
OBSOLETE. Catalysis of the reaction: 4-hydroxy-5-methyl-2-propyl-3(2H)-furanone + NADP = (2E)-4-hydroxy-5-methyl-2-propylidene-3(2H)-furanone + NADPH + H+.