Hemiacetal Formation Between Methanol And Cyclohexanone
CHEM 238 Winter, 2001 FINAL EXAM Name Prof. Sasaki Please circle your TA: Dirk Schweitzer , Tyan Carter, Carla McDowell 175 points TOTAL Good Luck! Note: Only answers in the box will be graded. _______________________________________________________________________ _ 1. (30) (a) Draw a stepwise mechanism for the following reaction. Use curved arrows to indicate the movement of electrons.
O O H3 C H+ HO OH CH3 O H3 C O CH3 O
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(b) Briefly explain the fact that, although hemiacetal formation between methanol and cyclohexanone is thermodynamically disfavored, addition of methanol to cyclopropane goes essentially to completion.
O CH3OH
HO OCH3
O
, cyclopropanone cyclohexanone
CHEM 238
page 2
Name
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2. (35) A β, γ-unsaturated carbonyl compound rearranges to a more stable conjugated α,β-unsaturated compound in the presence of either acid or base. …show more content…
(b) Propose a mechanism for the acid-catalyzed rearrangement.
CHEM
O O H3 C H+ HO OH CH3 O H3 C O CH3 O
.
(b) Briefly explain the fact that, although hemiacetal formation between methanol and cyclohexanone is thermodynamically disfavored, addition of methanol to cyclopropane goes essentially to completion.
O CH3OH
HO OCH3
O
, cyclopropanone cyclohexanone
CHEM 238
page 2
Name
.
2. (35) A β, γ-unsaturated carbonyl compound rearranges to a more stable conjugated α,β-unsaturated compound in the presence of either acid or base. …show more content…
(b) Propose a mechanism for the acid-catalyzed rearrangement.
CHEM