Jasmone 1 - ChemistforChrist

Synthesis of JASMONE
R
O
Ph H
Ph H
O
O
H
+ cat. KCN
+
CN
In the presence of:
cat.
CN
R
O
CN
O
Ph H
CN
H
CN
Ph
+ Ph
O
O
R
OH
Ph
Ph
OH
OH
CN
Ph
OH
CN
O Will react much slower with CN , because the
Carbonylfunction is stabilized by conjugation.
Stetter: Biomimetic Reaction
Tetrahedron Letters, 1974, 4505-4508
Review: Org. React. 1991, 40, 407-496
Biomimetic: Means copied from nature.
Vitamine B1 (Thiamine)
thiamine
HO
Cl -
N +
S
HO
NH 2
N
N
N
S
Bn
O
R 1
benzoine
Ph
Ph
O
Conj. Add.
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2
3
4 Me
O
Simplified by Stetter:
HO
S
Thiazolium-Salt
HO
X
N +
H
Ph
NaOH
N
S
Bn
OH
CN
O
Ph
more acidic
as the other
O
CN
R
R
OH
OH
CN
O
CN
Ph
O
O
Me
Me
Today also chiral versions
for asymmetric reactions.
This proton is quite acidic!
This anion replaces the role of the CN that we saw in the reaction above.