organic compounds
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The title synthetic analog of purine nucleosides, C16H16Cl2N4O7, has its acetylated β-furanose ring in a 3′β-envelope conformation, with the corresponding C atom deviating by 0.602 (5) Å from the rest of the ring. The planar part of the furanose ring forms a dihedral angle of 65.0 (1)° with the mean plane of the purine bicycle. In the crystal, molecules form a three-dimensional network through multiple C—HO and C—HN hydrogen bonds and C—Hπ interactions.
organic compounds
Open access
In the title compound, C11H20O8S, the furanose ring has a pseudorotation phase angle equal to 31.3° and assumes a 3T4 conformation, with deviations of 0.297 (4) and −0.152 (4) Å for the corresponding C atoms. The dioxolane ring adopts an envelope conformation. One of the O atoms is at the flap and deviates from the least-squares plane formed by the other four ring atoms by 0.405 (2) Å. The dihedral angle between the planar fragments of the rings is 63.53 (8)°. In the crystal, molecules are associated into sheets perpendiculer to the b axis by means of O—HO hydrogen bonds. A few weak C—HO interactions are also observed.
organic compounds
Open access
The title compound, C44H62O6S2 {systematic name: (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-3a-[(tosyloxy)methyl]icosahydro-1H-cyclopenta[a]chrysen-9-yl 4-methylbenzenesulfonate}, was obtained by tosylation of naturally occurring betulin. All the cyclohexane rings adopt chair conformations and the cyclopentane ring adopts a twisted envelope conformation, with the C atom bearing the tosylmethyl substituent forming the flap. In the crystal, molecules form a three-dimensional network through multiple weak C—HO hydrogen bonds.