Ch.21 Flashcards
Name this carboxylic acid derivative:
R - C =– N (triple bond)
nitrile
define carboxylic acid derivatives
compounds with functional groups that can be converted to carboxylic acids by a simple acidic or basic hydrolysis
______ are carboxylic derivatives in which the hydroxy group (-OH) is replaced by an alkoxy (-OR).
esters
what are lactones?
cyclic esters
Ammonium salts are converted to _____ at high temperatures.
amides
What are lactams?
cyclic amides
The atoms at the ends of the triple bonds (RCN) are ____ hybridized.
sp
the atoms at the ends of the triple bonds (RCN) have a bond angle of ____
180
Acid halides are also called what?
acyl halides
acid halides are ____ derivatives used in the synthesis of other acyl compounds such as esters.
activated
How are acid halides named?
replacing the -ic acid suffix name with -yl and the halide name
What does the word anhydride mean?
without water
Acid anhydrides are ___ derivatives of carboxylic acids
activated
How are anhydrides named?
replacing the word acid with anhydride
What is the nomenclature of multifunctional compounds? (the order of presedence)
acid > ester > amide > nitrile > aldehyde > ketone > alcohol > amine > alkene, alkyne
The physical properties of acid derivatives largely depends on what?
their polarity and hydrogen bonding properties
What is the polarity nature of amides?
strongly polar
Are acid derivatives soluble in common organic solvents?
yes
Most acid derivatives have C=O stretches between ____ and ____
1700 cm-1 and 1800 cm-1
Interconversion of acid derivatives occurs by _____ __________ ________
nucleophilic acyl substitution
Nucleophilic acyl substitutions are also called what?
acyl transfer reactions
What do nucleophilic acyl substitutions do?
transfer the acyl group to the attacking nucleophile
In a SN2 reaction, the bond forming and bond-breaking steps are simultaneous and the reaction is _______
endothermic
In the nucleophilic acyl substitution, the elimination of the alkoxide is highly ______.
exothermic
What is transesterification?
when one alkoxy group can be replaced by another with acid or base catalyst (large excess of desired alcohol used)
What is saponification?
the base-catalyzed hydrolysis of ester
How are soaps made?
by heating NaOH with a fat (triester of glycerol) to produce the sodium salt of a fatty acid
What can DIBAL ((i-Bu)2AlH) reduce?
esters to aldehydes
Grignard and organolithium reagents add twice to acid chlorides and esters to give _____ after protonation.
alcohols
What are Gilman reagents?
dialkylcuprates
Acid chlorides react once with dialkylcuprates to give _______
ketones
A reaction of a nitrile with a grignard or organolithium reagent produces a ______
ketone
What is a strong dehydrating agent that can eliminate the elements of water from a primary amide to give a nitrile.
POCl3 or P2O5
Five-membered lactams and six-membered lactams often form on _______ or adding a dehydrating agent to the appropriate amino acid.
heating
Beta-Lactams are what?
Unusually reactive, four-membered ring amides are capable of acylating a variety of nucleophiles
What are beta-lactams found in?
penicillins, cephalosporins, and carbapenems
How do beta-lactams work?
by interfering with the synthesis of bacterial cell walls
What is a thioester formed from?
a carboxylic acid and a thiol
Thioesters are _____ reactive toward nucleophilic acyl substitution than are normal esters.
more
How effective is the resonance overlap in a thioester compared to an ester.
The resonance overlap in a thioester is not as effective as that in an ester.
What is Coenzyme A (CoA)?
a thiol whose thioesters serve as a biochemical acyl transfer reagent
Acetyl CoA transfers an acetyl group to a _______, with coenzyme A serving as the leaving group.
nucleophile
What is acetyl choline?
a neurotransmitter, at the skeletal neuromuscular junction and those synapses when acetylcholine receptors are located
When acetylcholine esterase (AChE) is inhibited what happens?
excess acetyl choline builds up in the synapse
What are polycarbonates?
polymers bonded to the carbonate ester linkage
Reaction of toluene diisocyanate with ethylene glycol produces one of the most common forms of ___________.
polyurethanes
