Functionalization at C-5 of the triacetic acid lactone methyl ether,J, has been achieved by a transfer from the C-6 position. Thus, treatment of sulfides 12 with an excess of ethyl diazoaceta- te provides the pyrones 5 through [2,3] sigmatropic rearrangements. ... 4-Hydroxy-6-methyl-2-pyrone (triacetic acid lactone) , l-, is a 1 simple polyketide which is easily prepared' from the industrially ... M 2. Therefore, the lactones ,l-andAshould be ideal precursors for
