OCHEM EXAM THREE

What Does NABH4 Do?

-selective

reduces only aldehydes (primary alchol) and ketones to secondary alchols

What is Wittig’s Reaction, what does it do?

-converts aldehydes and ketones to alkenes

1.) R-BR 2.) Sn2 3.) PPH3—-R

What does LAH/LiAL4H do?

carboxylic acids and esters to primary alchols

reduces amides, to amines

Reduces nitriles to primary amines

What does PCC do?

-convert primary alcohols to aldehydes

- secondary alcohols to ketones.

WHat does Jones do?

Converts primary alcohols directly to carboxylic acid

Aldehydes to Carboxylic Acids

Cro3h2so4,h20/acetone

Decarboxylation

-works on beta keto acids

Acetoacetic Ester Synthesis

preparing ketones having one or two alkyl groups on the ɑ position:

 1.) NaoET/ R-X H30+, Heat

Enamine Alkylation

Formation of an enamaine using NH ring and aco; with h, h20 work up forms a Ketone

HVZ

br3/pbr3

replaces the H atom on a carboxylic acid (not on the OH) with a bromien atom

with H20, it adds on a secondary br on another alpha H

DiBAL-H , -78

-reduces nitriles (-C triple bond N) to aldehydes at low temps

-reduces esters to aldehydes

LiALH(Ot)Bu3

reduces acid chlorides to aldehydes

organometallics

R-MGX

Best bases Ever

NOT COMPATABLE with CARB. ACIDS

Ketones: Tertiary OH

Acid Chlorides + Anhydrides: two equivalents of to form tertiary alcohols (adds on two groups)

Grignards

form ketones from C triple bond N

R-MGBR/H30

Ozonolysis

cleavage of alkenes to carbonyl compounds

POCL3

converts primary amides into nitriles

Micheals Addition

1,4-addition

NAOCH3, CH3OH + R-X

The end product is much more acidic than the starting material. Therefore, this will result in mixed end over halogenated materials due to further deprotonation.

Better option would be using TSOH due to the fact that it is not strong enough to deprotonate a mono-halogenated product.

NaOMe is a reversiable base and alot of it remains in the solution in comparsion to the enolate. THereofre, it will result in an SN2 reaction. What would be better would be adding an irrev. Base such as LDA, -78 as it react fully without reversing and the enolate can attack the electrophile.

R-Li or R-MGBR are awseome bases that will deprotonate the carboxylic acid (oh) proton, resulting in the carboxylic acid forming again in work up. Change the carbox into an ester or an acid chloride as both are more E+ than the starting material