Reactions Flashcards
(24 cards)
NaBH4 will reduce
selectively ketones –> secondary alcohols
selectively aldehydes –> primary alcohols
BH4 will reduce
only carboxylic acids –> primary alcohols
NaBH4 and LiAlH4 reduce ketone to
secondary alcohol
NaBH4 and LiAlH4 reduce aldehyde to
primary alcohol
LiAlH4 reduces ester to
primary alcohol
Gabriel Synthesis
uses potassium phthalimide which is a protected form of ammonia and diethyl bromomalonate as starting materials to create alpha amino acid
during process: uses SN2 reaction, removes Br and removes potassium phthalimide
creates mix of L and D amino acid products
Strecker Synthesis
uses aldehyde, ammonium chloride (NH4Cl), and potassium cyanide (KCN) to create amino acid
creates an imine then aminonitrile and then alpha amino acid
creates mix of L and D amino acid products
What is the stereochemistry outcome of Strecker synthesis?
Mix of L and D because the imine and aldehyde do not contain stereocenter
transesterification
reaction between ester and alcohol that results in exchange of alkoxy and alcohol R groups
so will remain alcohol and ester, but they will be switched.
saponification
removal of alkoxy (oxygen connected to carbon + hydrogen compound) from an ester with a base.
Turns an ester into carboxylic acid + alcohol
aldol condensation
requires 2 carbonyl compounds (ketones and/or aldehydes) that will combine together on top of one another
form an alpha, beta- unsaturated carbonyl compound
acylation reaction
anhydrides and amines generate amides and carboxylic acids
HVZ reaction
Hell-Volhard-Zelinsky
uses PBr3
convert carboxylic acid to acyl bromide, add Br2 which will attack the double bond. The double bond will go to the OH complex, and the second Br removed the H so that it becomes a carbonyl. Adding H2O will remove the Br already there and replace with OH to make a carboxylic acid.
makes an alpha-bromoacid
Fischer esterification
esterification of a carboxylic acid by heating it with an alcohol in the presence of a strong acid as a catalyst
MAKES AN ESTER
Aldol condensation
forms an enolate by deprotonating the alpha carbon
a reaction at low temperature and with bulky base (LDA) will favor kinetic formation. Goes for more open alpha carbon
reaction at higher temperature with small base (NaH) will deprotonate a more substituted alpha carbon and form a thermodynamic product
What can be used to create a cyclic acetal?
1,2 diol and 1,3 diol
that is a linear substance that has 2 OH groups
retro-aldol reaction
catalyzed by base and heat
water is lost and the carbon-carbon bond between an alpha and beta carbon is broken, yielding two aldehydes, two ketones, or one of each
What increases the solubility of carboxylic acid in water?
by converting it into carboxylate anions by a base (ex: LiOH)
protic solvents
can hydrogen bond
include carboxylic acids
water/alcohols
ammonia/amines
can hinder nucleophilicity by protonating the nucleophile or through hydrogen bonding
aprotic solvents
can’t hydrogen bond
include: DMF, DMSO, acetone
Jones oxidation
oxidizes primary alcohols –> carboxylic acids
oxidizes secondary alcohols –> ketones
What makes a long chain the most acidic?
Want atoms with strong inductive effect (super electronegative) and that the electronegative element is located near the COOH group. The further away, the less acidic
reactivity of the carboxylic acid derivatives
acyl halide > anhydride > ester > amide
what will cause the absorption of wavelengths of light over a broad range?
conjugated pi system with the addition of electron donating amines and electron accepting carbonyls
