The compound exists in a chemical equilibrium with its tautomer 6-acetyl-1, 2, 3, 4-tetrahydropyridine that differs only by the position of the double bond in the tetrahydropyridine ring:
42.
Other possible isomers are dihydroxydislfane or hypodithionous acid HOSSOH, a linear chain, and thiothionyl hydroxide ( S = S ( OH ) 2 ) a tautomer where the hydrogen has moved from a sulfur to an oxygen.
43.
The tautomer, known as cyanic acid, HOCN, in which the oxygen atom is protonated, is unstable to decomposition, but in solution it is present in equilibrium with isocyanic acid to the extent of about 3 %.
44.
The enol forms of oxaloacetic acid are particularly stable, so much so that the two tautomer have different melting points ( 152 �C for the " cis " isoform and 184 �C for the " trans " isoform ).
45.
In the last decade, the GRID forcefield has been applied to other areas of Drug Discovery, including virtual screening, scaffold-hopping, ADME and pharmacokinetic modelling, optimisation of metabolic stability and metabolite prediction, as well as pKa and tautomer modelling.
46.
1, 2, 4-Oxadiazole, 1, 2, 5-oxadiazole, and 1, 3, 4-oxadiazole are known, but the 1, 2, 3-isomer is unstable ring-opens to form the diazoketone tautomer.
47.
Not a different tautomer or different stereochemistry etc . Once I've handed back the SDF file then the InChIKey can be used to search Pubchem for a direct match ONCE PubChem supports InChIKeys .-- talk ) 19 : 20, 16 January 2008 ( UTC)
48.
Although it was originally believed that 2-CMT in nature was ultimately derived from ornithine and acetic acid, subsequent research has indicated other pathways exist for the biosynthesis of 2-CMT . A ?-keto ester, 2-CMT exists in equilibrium with its keto enol tautomer.
49.
A compound containing a carbonyl group ( C = O ) is normally in rapid equilibrium with an enol tautomer, which contains a pair of doubly bonded carbon atoms adjacent to a hydroxyl ( " OH ) group, C = C-OH . The keto form predominates at equilibrium for most ketones.
50.
X-ray diffraction studies on the hydrogen urate ion in crystals of ammonium hydrogen urate, formed " in vivo " as gouty deposits, reveal the keto oxygen in the 2 position of a tautomer of the purine structure exists as a hydroxyl group and the two flanking nitrogen atoms at the 1 and 3 positions share the ionic charge in the six-membered pi-resonance-stabilized ring.
