Conformational properties of N-aryl-1-azacyclooctan-5- ones with a p-methyl, m-methyl, and p-methoxy group as a substituent have been studied by 1H-NMR, 13C-NMR and IR spectroscopies. Transannular interaction of the two functional groups have been examined from the ring inversion barriers and the carbonyl vibrational frequencies with reference to the corresponding data...

An antibiotic compound, CnH3406, was recently isolated in this laboratory from culture liquids of the Basidiomycete Pleurotus mutilus and named “pleuromutilin” (1). Chemical studies, described in this paper, have resulted in partial characterization of the oxygen atoms, and in the isolation of a reduction product, an oxidation product, and an alkali degradation product. Of the 5 oxygen atoms in...

The mononuclear Mn(CO)(5)X and binuclear Mn(2)(CO)(8)(μ-X)(2) manganese carbonyl halides have long been known for the halogens Cl, Br, and I. However, the corresponding manganese carbonyl fluorides (X = F) remain unknown. The structures and thermochemistry of such manganese carbonyl fluorides and their decarbonylation products have now been investigated using density functional theory. In all c...

this article reports a study of the thermo-oxidation and biodegradation in the soil of low-density polyethylene/starch films (ldpe/starch) by infrared spectroscopy: films of ldpe/starch blends of different composition (starch content range from 0 to 15% w/w),were prepared and exposed to thermo-oxidation at different temperatures at 80, 90 and 100°c,and buried in the soil of public dump during 3...

ÐThe molecular structures and barriers for the internal rotation around the OCÿCO single bond in four a-ketoamides and eight a-ketocarbonyls have been determined from the MP3/aug-cc-pVDZ and MP2/aug-cc-pVDZ calculations. a-Ketocarbonyls with non-bulky substituents adopt planar conformations with two carbonyl oxygens in s-trans arrangement. The s-cis conformation is signi®cantly less stable due ...

The crystal structure of the title triangulo-triruthenium compound, [Ru(3)(C(21)H(21)AsS(3))(CO)(11)], confirms that during the synthesis one equatorial carbonyl ligand is substituted by a monodentate arsine ligand, leaving one equatorial and two axial carbonyl substituents on an Ru atom. The other two Ru atoms each carry two equatorial and two axial carbonyl ligands. The three arsine-substitut...

The formation of hydroperoxides postulated in all the kinetic models for the low temperature oxidation of alkanes have been experimentally proved thanks to a new type of apparatus associating a quartz jet-stirred reactor through a molecular-beam sampling system to a reflectron time-of-flight mass spectrometer combined with tunable synchrotron vacuum ultraviolet photoionization. This apparatus h...

Samarium diiodide-water (SmI2-H2O) reagents have emerged as some of the most practical systems enabling reduction and reductive cyclizations of ketyl radicals. Recently, this reaction manifold has been extended to acyl-type radicals generated from cyclic polar carboxylic acid derivatives. However, the relationship between the fundamental electron- and proton-transfer steps in the generation of ...

In the title compound, C8H9BO4, the meth-oxy-carbonyl group is rotated out of the plane of the benzene ring by 7.70 (6)°. In the crystal, mol-ecules are linked via pairs of O-H⋯O hydrogen bonds, involving the boronic acid OH groups, forming inversion dimers. The dimers are linked via O-H⋯O hydrogen bonds, involving a boronic acid OH group and the carbonyl O atom, forming undulating sheets paral...

A series of 5alpha-androst-3-enes and 3alpha,4alpha-epoxy-5alpha-androstanes were synthesized and tested for their abilities to inhibit aromatase in human placental microsomes. In these series the original C-17 carbonyl group was replaced by hydroxyl, acetyl and hydroxyimine groups. Inhibition kinetic analysis on the most potent steroid of these series revealed that it inhibits the enzyme in a ...