OCHEM: Synthesis of 4-Methylcyclohexene from 4-methylcyclohexanol

Whats the purpose of the lab

synthesize 4-methylcyclohexene from 4-methylcyclohexanol (which is a secondary alcohol)

What type of reaction is observed

an acid dehydration of a secondary alcohol

why do we add phosphoric acid to sulfuric acid

phosphoric acid reduces the extensive charring from just using sulfuric acid

• a bit of sulfuric acid is used to make reaction proceed faster

What does the separatory funnel have 

the top layer is the organic layerand the bottom layer is the aqueous layer.

what is the purpose of the saturated NaCL in the separatory funnel?

to remove large amounts of dissolved water and to minimize the amount of the organic product that dissolves in the aqueous layer

What layer has been extracted after using separatory funnel technique 

organic top layer was extracted

whats the purpose of anhydrous sodium sulfate

a drying agent that removes minute particles of water from organic solvent

why do we perform two distillation processes

1. to get the product from the reaction mixture & work with Le Chatliers’s principle 

2. to purify product

why do we test the presence of cyclohexene with bromine

its a saturation test to test if the product produced contained a double bond

• if it goes from red to colorless, then theres the presence of a double bond

mechanism for dehydration of 4-methyl cyclohexanol catalyzed by phosphoric acid

cyclohexanol dehydration

1-methylcylohexanol dehydration

2-methylcyclohexanol

2,2-dimethylcyclohexanol

1,2-cyclohexanediol dehydration