Satlow Michael, Williard Paul G
Program in Judaic Studies-Box 1826, Brown University, Providence, Rhode Island 02912, USA.
Department of Chemistry-Box H, Brown University, Providence, Rhode Island 02912, USA.
Acta Crystallogr E Crystallogr Commun. 2023 Aug 4;79(Pt 9):786-790. doi: 10.1107/S2056989023006497. eCollection 2023 Sep 1.
The structures of three racemic (tetra-hydro-[1,3]dioxino[5,4-][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methyl-sulfon-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-][1,3]dioxine, CHOS, , 4-[(benz-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-][1,3]dioxine, CHO, , and 4-[(anilinocarbon-yl)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-][1,3]dioxine, CHNO, . Mesylate ester at 173 K has triclinic symmetry and both benzyl ether at 173 K and phenyl urethane have monoclinic 2/ symmetry. These structures are of inter-est because of the conformation of the -fused tetra-oxadeca-lin ring system. This -bi-cyclo-[4.4.0]decane ring system, -deca-lin, 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 dihy-droxy aldehyde and tosyl-ate analogs.
