Formation of Heterocyclic and Polycyclic Compounds from Amino Alcohols and Dialdehydes

Amino alcohols typically react with aldehydes to produce oxazolidines. It was hypothesized that the condensation of several commercially available amino alcohols with dialdehydes would produce a series of bicyclic oxazolidines containing two secondary amines. However, there were remarkable differences in the type of products formed depending on the structure of the dicarbonyl compounds and the reaction conditions. When linear aliphatic dialdehydes such as glyoxal were used, the expected bis‐oxazolidines were not produced; instead, polycyclic structures or oxazines were formed. However, when cyclic dialdehydes such as 1,3/1,4 cyclohexane dicarboxaldehyde were used, they resulted in products bearing the desired oxazolidine moieties.     

Structure of 3,3:6,6-dibutano-3a-methyl-6a-phenyltetrahydrofuro[3,2-b]furan-2,5-dione

Journal of Structural Chemistry - In the interaction of methyl 1-bromocyclopentanecarboxylate with zinc and 1-phenylpropan-1,2-dione,...     

Assignment of the absolute configuration of fischerin by computed nmr chemical shifts

The unassigned configurations of a toxic metabolite to mammals extracted from Neosartorya fischeri (fischerin) in C19, C20, C21, and C22 are assigned as R, R, R, and S, respectively. In this assignment, the extensive ab initio calculations followed by chemical shift computations are performed. Computed chemical shifts are correlated to experimental ones in order to find the correct configuration shown here.     

Structural characterisation and photoluminescence of a pyridine–diimine compound

A pyridine–diimine compound N,N′-[pyridine-2,6-diyldi(E)methylylidene]bis(4-chloroaniline) is synthesised by a Schiff base condensation of 2,6-diformylpyridine with 4-chloroaniline in methanol and characterised by spectroscopic and analytical techniques. The molecular structure of the compound is determined by the single crystal X-ray diffraction study. The compound crystallizes in the monoclinic crystal system, I2/c space group with unit cell parameters a = 7.0843(12) Å, b = 6.1909(11) Å, c = 36.262(6) Å, β = 91.576(3)°, V = 1589.8(5) ų and Z = 4. There is an intermolecular hydrogen bonding in the molecule resulting in a 1D hydrogen bonding chain and these hydrogen bonding chains are linked by Cl…HC(aromatic) interactions forming a 2D network. Crystal packing of the compound is determined by Cl…HC and π–π interactions. In the fluorescence emission spectra in CH₃CN, DMF, DMSO and EtOH, the compound shows only one emission maximum.     

1,7-difluoro-1,1,3,5,7,7-hexanitro-3,5-diazaheptane: Crystal structure and sensitivity to mechanical actions

The X-ray crystallographic analysis of 1,7-difluoro-1,1,3,5,7,7-hexanitro-3,5-diazaheptane has been carried out. We have also determined its sensitivity to mechanical actions and a set of calculated and experimental data on explosion characteristics.