CH 18/19 reagents

LiAH4 (LAH)

Makes carbonyl an alcohol by adding an H to the C in the carbonyl

NaBH4

Makes carbonyl an alcohol by adding an H to the C in the carbonyl

Lithium Reagents (anything with Li)

Makes carbonyl an alcohol and adds carbon chain from the Li

Grignard Reagents (anything with MgBr)

• Added to cyanide-containing compounds

• Turns triple bond between C & N to C=N and adds carbon chain from the MgBr

• IF ACIDIC CONDITIONS (H3O+), CN bond will be converted to a C=O instead of maintaining C=N

Wittig Reagents (PPh3 with a negatively charged carbon atom (that will act as the nucleophile))

• Swaps C=O for C=C(CH3)2

Sulfonium Ylides (S-C)

• Form an epoxide at C of C=O

Hemiacetal formation

• Can be done under neutral or acidic/basic conditions, with acidic/basic conditions producing a faster reaction due not forming an intermediate with two charged atoms

• Neutral = Nucleophilic addition, H transfer, H transfer

• Acidic/basic = H transfer, nucleophilic addition, H transfer

• DONE WITH AN ALCOHOL

Acetal formation

• Prefers acidic conditions (activation of the carbonyl group)

• Done with an ALCOHOL WITH ACIDC CONDITIONS

• Reversible based on Le Chatlier’s Principle

Reductive Amination

• Removes one hydrogen from NH? Group (NH3 -> NH2, etc.)

• Replaces carbonyl (C=O) with whatever the reagent is minus one H

Wolff Kishner Reduction (N2H4)

• RARE reaction that removes carbonyl group entirely (replaced with 2H)

Robinson Annulation

Intramolecular