Syntehsis of Alcohol

Richard Zhou 10/17/11 CH 237-011 Lab Report #4 Dehydration of Methylcyclohexanols Results 1.) 4-methylcyclohexanol = .150 mol mixture of 1-methylcyclohexene, 3-methylcyclohexene, 4-methylcyclohexene = (.150mol) * (96.2g/mol) = 14.43 g The theoretical yield is 14.43g since phosphoric acid acts as a catalyst and the methylcyclohexanol is the only reagent. 2.) product yield 1st fraction = 3.5g 2nd fraction = 3.08g Total = 6.58g (6.58g) / (14.43g) = 45.6% yield 3.) The alkenes boiled from a range of 100°C to 118°C but stabilized around 110°C. 4.) All fractions were contaminated with the starting alcohol. An unknown peak appeared in every graph of the gas chromatography and this peak is most likely from a single impurity. Average product distribution from 2-methylcyclohexanol 1st fraction unknown = 6.4% 1-methylcyclohexene = 65.8% 3-methylcyclohexene = 9.6% 2-methylcyclohexanol = 18.2%

2nd fraction unknown = 3.7% 1-methylcyclohexene = 42.4% 3-methylcyclohexene = 27.5% methylenecyclohexane = 5.5% 2-methylcyclohexanol = 20.9% Average product distribution from 4-methylcyclohexanol 1st fraction unknown = 6.4% 1-methylcyclohexene = 74.4% 4-methylcyclohexene = 5.4% 4-methylcyclohexanol = 13.8% 2nd fraction unknown = 6.4% 1-methylcyclohexene = 72.7% 4-methylcyclohexene = 15.2% 4-methylcyclohexanol = 5.7% Discussion 1.) The problem presented in this lab is to confirm the “Evelyn Effect” during the dehydration of 2-methylcyclohexanol and to test to see if the Evelyn effect occurs in the dehydration of 4methylcyclohexanol. The Evelyn effect is when the products of dehydration of 2methylcyclohexanol are collected in two fractions and the product distribution of each fraction is different. The reaction is carried out and two fractions are collected. Half the lab used 2-

methylcyclohexanol and the other half used 4-methylcyclohexanol. Phosphoric acid was used as the catalyst. The reaction was run in a simple distillation apparatus. The first fraction was collected when the...