title: Eclipsed acetaldehyde as a precursor for producing  vinyl alcohol.
abstract: The MP2 and DFT/B3LYP methods at 6-311++G(d,p) and aug-cc-pdz basis sets have been used to probe the origin of relative stability preference for eclipsed acetaldehyde over its bisected counterpart. A relative energy stability range of 1.02 to 1.20 kcal/mol, in favor of the eclipsed conformer, was found and discussed. An NBO study at these chemistry levels complemented these findings and assigned the eclipsed acetaldehyde preference mainly to the vicinal antiperiplanar hyperconjugative interactions. The tautomeric interconversion between the more stable eclipsed acetaldehyde and vinyl alcohol has been achieved through a four-membered ring transition state (TS). The obtained barrier heights and relative stabilities of eclipsed acetaldehyde and the two conformers of vinyl alchol at these model chemistries have been estimated and discussed.
authors.affiliation: Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia. oabdelkarim@kau.edu.sa.
authors.forename: Osman I
authors.initials: OI
authors.lastname: Osman
authors.forename: Abdulrahman O
authors.initials: AO
authors.lastname: Alyoubi
authors.forename: Shabaan A K
authors.initials: SA
authors.lastname: Elroby
authors.forename: Rifaat H
authors.initials: RH
authors.lastname: Hilal
authors.forename: Saadullah G
authors.initials: SG
authors.lastname: Aziz
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry*; D000438:Alcohols / Q000138:chemical synthesis / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular
chemical_list: D000438:Alcohols; D000079:Acetaldehyde