Dehydration Of 2-Methylcyclohexene Lab Report

The objective of this experiment was to perform a dehydration of 2-methylcyclohexanol. The result would be a mixture of 1-methylcyclohexene and 3-methylcyclohexene. There can also be a third product, methylenecyclohexane, though this would be identified using gas chromatography. An acid-catalyzed dehydration of 2-methylcyclohexanol occurs via an E1 mechanism; acids will react with 2-methylcyclohexanol to eliminate the alcohol (OH group). This causes the formation of a carbocation and an alkene will form near the charge. Based on the position of the charge, two or three products can be produced. After the protonation of the alcohol group on 2-methylcyclohexanol, resulting in water (good leaving group), a double bond will form, producing 3-methylcoyclohexene.

In this case, a hydride shift will occur between the hydrogen attached to the charge and the hydrogen near the methyl group. The result is a tertiary carbocation and a double bond will form near the substituent; the alkene with the most substituted group is the major product, or 1-methylcyclohexene. According to Zaitsev’s rule, the alkene with the most substituted group would be the major product, because it is the most stable. The formation of the tertiary carbocation could also produce the third product, though in less quantity because it forms a less substituted alkene (minor product). In order to proceed with this reaction, 2-methylcyclohexanol is combined with the acids, phosphoric and sulfuric acid, and heated under distillation. During distillation, the circulation of water in the condenser would prevent any loss of