Dehydration of Alcohols

A

Acid protonates

Converts strong base into weak base (bad to good leaving group)

Water departs forming C+ (rate determining)

Major product is the most substituted (stable) alkene

Tertiary is the easiest to dehydrate because of their C+

Temperatures needed Alcohol

The cation is a secondary cation.

It can rearrange to a tertiary (our best friend) to retain a stable charge

Thus rearranging to a more stable product.

The product above forms abour 2.99% of the time.

Alcohol Eq

The E2 and SN2 dehydration of primary alcohols can compete.

When the water departs a primary alkane, it can eliminate or substitute for the Alkane

If it eliminates, than we have this product

CH3CH2OH → CH2=CH2

If it substitutes, another alkane-o-hol is added

CH3CH2OH + CH3CH2OH → CH3CH2OHCH2CH3

ether