Stephanie Castro
Dehydration of Cyclohexanol
Introduction:
An E1 reaction exhibits first-order kinetics. The most straightforward explanation for the
observed first-order kinetics is a two-step reaction: the bond to the leaving group breaks
first before the o bond is formed. Heterolysis of the C – X bond forms an intermediate
carbocation. This is the same first step as the SN1mechanism. It is responsible for the
first-order kinetics because it is rate-determining. A base removes a proton from a carbon
adjacent to the carbocation (a β carbon). The electron pair in the C – H bond is used to
form the new π bond. In an E1 reaction, the leaving group comes off before the a proton is
removed, and the reaction occurs in two steps. In an E1 reaction, a base removes a proton,
forming a new o bond. Alkyl halides undergo elimination reactions with Brønsted–Lowry
bases. The elements of HX are lost and an alkene is formed. More substituted halides react
fastest. Weaker bases such as H2O and ROH favor E1 reactions. A better leaving group
makes the reaction faster because the bond to the leaving group is partially broken in the
rate-determining step. Polar protic solvents that solvate the ionic intermediates are needed.
The purpose of conducting this experiment is to observe and understand the dehydration of
cyclohexanol.
Reaction and Mechanism;
Chemical Properties & Safety
Cyclohexanol
B.P: 160.8
Density: 0.964 g/ml
MW: 100.158 g/mol
Hazards: Irritant, Permeator. Very hazardous in case of ingestion, skin contact or inhalation
Cyclohexene
B.P: 83.0
Density: 0.81 g/ml
MW: 82.143 g/mol
Hazards: Hazards: Irritant, Permeator. Very hazardous in case of ingestion, skin contact or
