the condensation of glyoxal with benzylamine in the presence of formaldehyde leads to 2,4,6,8-tetrabenzyl-2,4,6,8-tetraazabicyclo [3.3.0] octan (6) in methanol. the scopes and limitations of the reaction have been determined. at low temperatures, a mixture of (6) and diol (7) is formed.

Condensation of glyoxal, formaldehyde and anilines lead to the formation of 2,4,6,8- tetraphenyl and substituted phenyl 2,4,6,8-tetraazabicyclo [3.3.0] octanes. The reactions are sensitive to pH and temperature. Ortho derivatives of anilines do not participate in this condensation. X-ray structural determination reveals a cis-dienvelope geometery about the two fused rings.

condensation of glyoxal, formaldehyde and anilines lead to the formation of 2,4,6,8- tetraphenyl and substituted phenyl 2,4,6,8-tetraazabicyclo [3.3.0] octanes. the reactions are sensitive to ph and temperature. ortho derivatives of anilines do not participate in this condensation. x-ray structural determination reveals a cis-dienvelope geometery about the two fused rings.

The title compound, C(16)H(20)Cl(2)O(8), contains a central bicyclo-[2.2.2]octane skeleton with slightly twisted conformation. In this structure, the C-C bond lengths are in the range 1.525 (2)-1.552 (2) Å. Two sides of this skeleton have cis,cis acet-oxy substituents and the Cl atoms have a trans arrangement. An extensive network of weak C-H⋯O interactions stabilizes the crystal structure.

In the structure of the title compound, C(20)H(34)O(2)Si, a cis,trans,cis,cis-[4.5.5.5]fenestrane derivative, the geometry of the central C(C)(4) substructure shows considerable distortion from an ideal tetra-hedral arrangement towards planarity, with two opposite bridgehead bond angles of 128.87 (18) and 122.83 (17)°. The other bridgehead angle of the trans-bicyclo-[3.3.0]octane subunit is als...

PR04.MZ 8-(4-fluoro-but-2-ynyl)-3-p-tolyl-8-aza-bicyclo[3.2.1]octane-2-carboxylic acid methyl ester (1) and LBT999 8-((E)-4-fluoro-but-2-enyl)-3b-p-tolyl-8-aza-bicyclo[3.2.1]octane-2beta-carboxylic acid methyl ester (2) are selective dopamine reuptake inhibitors, derived from cocaine. Compounds 1 and 2 were labelled with fluorine-18 at their terminally fluorinated N-substituents employing micro...

A bicyclo[2.2.2]octane derivative containing both a tertiary amide and a methyl ester (1) was shown crystallographically to adopt a conformation in which the amide is in the cis configuration, which is sterically disfavored, but electronically favored. The steric strain induces a significant torsion (15.91) of the amide, thereby greatly increasing the solvolytic lability of the amide to the ext...

In the molecule of the title compound, C(18)H(32)N(2)O(4), the central bicyclo-[3.3.0]octane (octa-hydro-penta-lene) has a rigid ring junction. Both rings of the bicyclo-[3.3.0]octane unit adopt an envelope conformation, and the flexible tert-butyl-carbamoyl side chains each have an extended conformation. Such a constrained bicyclo-[3.3.0]octane aliphatic template is of inter-est with respect t...

A new class of aminocyclitol derivatives with the bicyclo[4.2.0]octane skeleton was synthesized starting from cyclooctatetraene. Photooxygenation of trans-7,8-diacetoxy- and cis-7,8-dichlorobicyclo[4.2.0]octa-2,4-diene afforded the bicyclic endoperoxides. Reduction of the latter with thiourea followed by a Pd(0) catalyzed ionization/cyclization reaction gave the corresponding oxazolidinone deri...

The condensation of glyoxal with benzylamine in the presence of formaldehyde leads to 2,4,6,8-Tetrabenzyl-2,4,6,8-Tetraazabicyclo [3.3.0] octan (6) in methanol. The scopes and limitations of the reaction have been determined. At low temperatures, a mixture of (6) and diol (7) is formed.