New Synthesis of the Cyclopentane Ring 1687 eluate (B), Table I, in vacuo to a dry sirup and acetylation of this sirup resulted in the isolation of a colorless sirup rotating +93.4°(c, 2 in chloroform). This acetate, dissolved in ethanol, crystallized overnight at 25°. The total yield of pure octaacetyl-6 -[ a -d -glucopyranosyl ] -/3 -D-glucose, [a]25d +98.0°(c, 2 in chloroform), m. p. 143°, was 9.2 g. or 77%. e Crystallization of 6-[a-D-Glucopyranosyl]-D-glucose.-Six grams of (IV), [«¡25°d +98.0°in chloroform, was deactylated catalytically with barium methylate at 0°. The barium was precipitated with 0.5 TV sulfuric acid and removed by filtration as barium sulfate. A colorless solution, pH 7.0, resulted. Concentrated in vacuo to a sirup and taken up in ethanol the deacetylated material crystallized during several days as long prisms. Recrystallized under similar conditions the sugar was separated by filtration, washed and dried to constant weight at 98°. The dry crystalline substance melted at 120 °and had an equilibrium [<*]2Sd value (c, 1.2 in water) of +120°mutarotating downwards. Its Jlfcu value (c, 1) was 97%; yield, 2.3 g.

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