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By P. A. FINAN and G. A. FOTHERGILL.Furan, 2-methylfuran, and 3-methylfuran with isovaleric anhydride under Priedel-Crafts conditions give the a-isovalerylfurans. The last of these (I ; K = H, R' = Me) was identical with elsholtzia ketone. 2-Acetyl-3-methylfuran (111) and 2-acetyl-4-methylfuran (V; R = Me) were prepared by unambiguous routes ; the product obtained by acetylation of 3-methylfuran under Friedel-Crafts conditions was identical with the ketone (111), and contained no trace of the isomer (V; R = Me).EISHOLTZIA KETONE, found in the essential oils of Elsholtzia cristata Willd. ,2 Perilla .frictescens Brit.: and in Elsholtzia oldhami Heinsl.,* has structure (I; R = H, R' = Me), 011 the basis of degradative5 and synthetic work.6 The tedious nature of the latter prompted us to attempt a synthesis by a Friedel-Crafts reaction on 3-methylfuran, an approach which had been successful for the synthesis of the corresponding dehydrocompound, naginata ketone.Treatment of furan with isovaleryl chloride in the presence of boron trifluoride in ether gave 2-isovalerylfuran (I; I 3 = R' = H) in 10% yield. When isovaleric anhydride was used the yield of ketone was increased to 55% (all yields are based on the anhydride). Similarly 2-methylfuran and isovaleryl chloride gave 2-isovaleryl-5-methylfuran (I ; R = Me, R' = H) in only 15% yield whereas use of isovaleric anhydride gave a 30:/, yield of

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Tri-0 -acetyl-2-0 -methyl -p -D -glucop yranoside.By P . A. FINAN and C. D. WARREN. Methylation of methyl 2,4,6-tri-O-acetyl-p-~-glucopyranoside with methyl iodide and silver oxide gave a high yield of methyl 3,4,6-tri-O-acetyl-2-O-methyl-P-D-ghcopyranoside, the structure of which was proved by an alternative synthesis.