Deuterium Isotope Studies of the Dehydration Alcohols by Reaction With Triphenylphosphine-Tetrachloromethane
Document Type
Article
Publication Date
1-1-1991
Description
The reactions of 2-butanol, 2-butanol-2d1, erythro-2-butanol-3d1, (EB), 2-methyl-2-propanol (2M2P), and 1,1,1,3,3,3-hexadeuterio-2-methyl-2-propanol (HDMP), respectively, with CCl4, and Ph3P in a polar or non-polar solvent in the temperature range of 36-85°C was studied. For 2-butanol the fraction of dehydration products increased with temperature; the opposite temperature effect was observed for (2M2P). Dehydration was the dominant pathway for (2M2P) (85-95%) but substitution (of OH by Cl) was dominant for 2-butanol (75-95%). Deuterium retention in the butenes from the conversion of (EB) indicated that 98% or more of the dehydration followed an anti-elimination pathway, and there was a preference for Saytzeff elimination. An isotope effect for deuterium elimination (kH/kD) for the alkene-forming step for (EB) and (HDMP) was about 2.0, and neither temperature nor solvent polarity appeared to have an effect on (kHkD) in the range investigated. Surprisingly, there was an isotope effect for the relative rate of the formation of alkyl halide from (EB) but not from (HDMP).
Citation Information
Dabbagh, Hossein A.; Franzus, Boris; Huang, Thomas T.S.; and Davis, Burtron H.. 1991. Deuterium Isotope Studies of the Dehydration Alcohols by Reaction With Triphenylphosphine-Tetrachloromethane. Tetrahedron. Vol.47(6). 949-960. https://doi.org/10.1016/S0040-4020(01)80935-2 ISSN: 0040-4020