The 2,4,6-tri-0-acetates of methyl 3-deoxy-3-nitro-p-D-glucopyranoside, -galactopyranoside, and-mannopyranoside, the 2-0-acetates of the 4,6-0-benzylidene derivatives of the two first-mentioned glycosides, and the tetra-0-acetatc of 1,4-dideoxy-1,4-dinitro-r~eo-inositol arc prepared by boron trifluoridecatalyzed acetylation. The advantages of the procedure over acetylation in pyridine are pointed out. The gl~rco triacetate, when produced in the presence of pyridine, is acco~npanied by crystalline by-products of a novel nature. It suffers undetermined changes by the action of activated alumina, and in dilute aqueous alkali it is instantly converted into an unsaturated nitronate.

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The bridging chlorine atoms are about 0.3 A further away from the tellurium than the terminal ones. This is much more pronounced in TeCl, (0.6 A), which is tetrameric in the crystalline state and has a cubane-type structure with Te having a coordination number 6L21; the Te-Cl distances of the terminal chlorine atoms have a value of 2.31 A, and those of the bridgingchlorine atoms 2.93 A. A uniform value of 2.51 A[3*41 was determined for the Te-Cl distance in (CH3)2TeC12, which crystallizes as monomer. To a good approximation one can assume the ions TeC13+ and C1-in the case of TeC1412] and four predominantly covalent bonds in the case of (CH3)2TeC12.Compound ( Z ) , having one Te-C bond, lies between TeCl,, which has no Te-C bonds, and (CH3),TeC12 which has two Te-C bonds; this explains the average Te-Cl distance of 2.38 A for the terminal Cl atoms. According to this, C1-ions (on twofold axis) and ClCH,-CH,TeCl; ions (on mirror plane) alternate along the polymer chain.Thus we find similar bonding characteristics as in TeF4I51. Separation into TeX; and X-ions, however, seems to be indicated more prominently in our case. It appears to us to be unjustified to speak of a predominantly ionic lattice.