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The structures of three racemic (tetrahydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methylsulfonyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C₈H₁₄O₇S,1, 4-[(benzyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C₁₄H₁₈O₅,2, and 4-[(anilinocarbonyl)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C₁₄H₁₇NO₆,3. Mesylate ester1at 173 K has triclinicP\overline{1} symmetry and both benzyl ether2at 173 K and phenyl urethane3have monoclinicP2₁/csymmetry. These structures are of interest because of the conformation of thecis-fused tetraoxadecalin ring system. Thiscis-bicyclo[4.4.0]decane ring system,i.e. cis-decalin, can undergo conformational equilibration. In the two most stable conformers, both six-membered rings adopt a chair conformation. However, there are significant consequences in these two stable conformers, with heteroatom substitution at the 1,3,5,7-ring positions as described. Only one conformation, denoted as `concave' or `inside', is found in these crystal structures. This is consistent with previously reported structures of the 1,1-geminal dihydroxy aldehyde and tosylate analogs. 

A mononuclear W( iv ) bis-dithiolene complex stabilized by an oxo ligand shows a reductive reactivity toward CO 2 , from which formate and a dinuclear W( v ) complex are generated. An unusual structural rearrangement was observed during the reaction. Structural and spectroscopic characterization for a novel triply bridged dinuclear W( v ) complex is reported.