Grignard Reactions, Oxidation and Reduction Reactions

what are grignard reactions?

organometallic reaction - metals used as reagents

what reagent is used in grignard reactions?

MgBr

what does the grignard reagent form?

new carbon-carbon bond

since metals are positive (MgBr), what is acting as a great nucleophile?

the carbon attached to the metal

what are the 2 reagents used in grignard reaction?

R group attached to MgBr and H3O+

how many steps are in the mechanism of a grignard reaction with esters and acid chlorides?

4 steps

what does 2 equivalents mean?

there is 2 of that reagent

what is the key difference between a grignard reaction with epoxides and a reaction with esters?

with epoxides, a new carbon-carbon bond forms so one of those carbons is removed from OH

in an epoxide, which carbon is the electrophile?

the less substituted/easier to get to carbon

what is an oxidation reaction?

gain of bonds to oxygen in a molecule or a loss of bonds to hydrogen

what is a reduction reaction?

loss of bonds to oxygen in a molecule or a gain of bonds to hydrogen

what functional group is common to be oxidized?

alcohols

what is the alcohol functional group?

OH

what does a primary alcohol oxidize to?

aldehyde

what does an aldehyde oxidize to?

carboxylic acid

what does a secondary alcohol oxidize to?

ketone

what does a ketone oxidize to?

no reaction

what does a tertiary alcohol oxidize to?

no reaction

why doesn't a tertiary alcohol oxidize - why does no reaction occur?

the central carbon can't have 5 bonds

when will no more oxidation occur?

when the number of bonds to the main carbon are maxed out and there's no more hydrogens attached

what are the 2 common reagents in oxidation?

H2CrO4 and PCC

what is H2CrO4 (chromic acid)?

Jones reagent - used in oxidation reactions; this reagent is so strong that it will cause the reactant to oxidize straight to a carboxylic acid

what is PCC?

a weak reagent used in oxidation reactions; reactant stops oxidizing at the aldehyde

what reagent is used in the oxidation of alkenes that produces an epoxide?

mCPBA

what is an epoxide?

a triangle with 2 carbons and oxygen at the point

what reagents are used in the oxidation of alkenes that cut the double bond in half with the 2 oxygens at each end?

O3 and DMS

what reagents are used in the oxidation of alkenes that cut the double bond in half and oxidizes to 2 carboxylic acids?

O3, H2O2 and NaOH, H3O+

what is an ester?

double bond oxygen attached to a carbon and oxygen which is attached to another carbon

reagents with a lot of hydrogens are _______________.

reductants

reagents with a lot of oxygens are _______________.

oxidants

what will an alcohol reduce to?

no reaction

what will a ketone reduce to?

secondary alcohol - OH attached to 2 R groups

what does the reduction of ketones or aldehydes produce?

alcohols

what is a weak reducing reagent used in reduction reactions?

NaBH4, H3O+

what does a carboxylic acid or ester reduce to?

aldehyde

what does an aldehyde reduce to?

primary alcohol - OH attached to 1 R group

will NaBH4 reduce carboxylic acids or esters?

no because it is a weak reducing reagent

what is a strong reducing agent in reduction reactions?

LiAlH4, H3O+

will LiAlH4 reduce carboxylic acids or esters?

yes because it is a strong reducing reagent

will H2 and Pt reduce an acid or ester in a reduction reaction?

no

will H2 and Pt reduce a ketone or aldehyde in a reduction reaction?

yes

what 2 different reagent types will reduce ketones and aldehydes?

NaBH4, H3O+; H2, Pt

what reagents are used in the reduction of alkenes?

H2, Pt or Pd/c

can you reduce a benzene ring?

no

what will happen if you reduce an alkene that also has a ketone?

the double bond will reduce but the ketone is left alone

what are the reagents used in the reduction of alkynes?

H2, Pt or Pd/c; H2, Lindlar's catalyst

what does the reduction of alkynes produce?

4 new bonds to hydrogen

what does the reduction of alkenes produce?

2 new bonds to hydrogen