Download Reaction Name: E1 Dehydration of 2-methylpropan-2

Reaction Name: E1 Dehydration of 2-methylpropan-2-ol
Conversion: Alcohol to Alkene
______________________________________________________________________________
General Form:
CH3
CH2
H2 SO4
H3C
H3C
OH
CH3
CH3
______________________________________________________________________________
Mechanism:
CH3
H 3C
CH3
OH
+
OH
H O S
H 3C
O
CH3
O
CH3
CH3
H 3C
CH3
O
O
H
+
+
H
HO S O
O
-
CH3
O
H
+
endothermic
H
H 3C
C
+
CH3
H
H
H 3C
CH2
H
C
+
+
O H
H
CH3
H
+
H 3C
+
H O H
CH3
______________________________________________________________________________
Notes: This reaction is often referred to as acid catalyzed and for our elementary purposes this is
correct because the reaction needs an acidic environment. The E1 mechanism is only for
secondary and tertiary alcohols. Rearrangement will occur in some cases so look out. Do not
forget about Zaitsev and regioselectivity.
______________________________________________________________________________
Examples: Francis (textbook) p 202.
References: Chip Le and the Textbook.