CH 3orsellinic acidCOOHHO OHProblems 839- a. What carboxylic acid would be formed if the malonic ester synthesis were carried out with one equivalent of malonic ester,one
equivalent of 1,5-dibromopentane, and two equivalents of base?
b. What carboxylic acid would be formed if the malonic ester synthesis were carried out with two equivalents of malonic ester,
one equivalent of 1,5-dibromopentane, and two equivalents of base? - A Cannizzaro reactionis the reaction of an aldehyde that has no with concentrated aqueous sodium hydroxide. In this
reaction, half the aldehyde is converted to a carboxylic acid and the other half is converted to an alcohol. Propose a reasonable
mechanism for the following Cannizzaro reaction: - Propose a reasonable mechanism for each of the following reactions:
a. b.- The following reaction is known as the benzoin condensation. The reaction will not take place if sodium hydroxide is used instead
of sodium cyanide. Propose a mechanism for the reaction. - Orsellinic acid, a common constituent of lichens, is synthesized from the condensation of acetyl thioester and malonyl thioester. If
a lichen were grown on a medium containing acetate that was radioactively labeled with at the carbonyl carbon, which carbons
would be labeled in orsellinic acid?
(^14) C
CH
O
CCH
OH
O
NaC
benzoin
CH 3 OH
N
O
O
H 3 O+
HO
OH
O O O
H 3 O+
O
CH
concentrated NaOH
O
CO− + CH 2 OH
a-hydrogens
O
HN
O
O
N
H
CH 2 CH 2 CHCH 3
CH 3
CH 2 CH 3
Amytal
Hagemann’s ester
COCH 2 CH 3
CH 3
O
O
- A compound known as Hagemann’s estercan be prepared by treating a mixture of formaldehyde and ethyl acetoacetate first with
base and then with acid and heat. Write the structure for the product of each of the steps.
a. The first step is an aldol-like condensation.
b. The second step is a Michael addition.
c. The third step is an intramolecular aldol condensation.
d. The fourth step is a hydrolysis followed by a decarboxylation. - Amobarbital is a sedative marketed under the trade name Amytal®. Propose a synthesis of amobarbital, using diethyl malonate and
urea as two of the starting materials.