alpha carbon rxns

what is acid tautomerization mech

always want pos charge on a carbon bc acidic conditoins

what is base tatuo mech

always want neg charge on carbon bc basic cond/

what are two ways to form enolate from ketone

use NaOH to get ketone and enolate

use LDA to get enolate

what are the two nucleophilic sties of an enolate

what is the difference between the reactants in aldol condensation and aldol addition rxn

there is heat in the condensation reaction

what is alpha halogenation in acidic conditions

have ketone to form enolate

reagent: H3O, Br2

want more sub alkene

what is the Hell Volhard Zelinsky reaction (HVZ)

add BR at alpha pos of carbox acid

reagent: 1)PBR3,BR2 2)H2O

what is alpha halogenation rxn in basic conditions

no need to form enolate

reagents: NaOH, Br2

what is the haloform reaction for halogenation in basic cond.

ketone to carbox acid

only works when 3H can be replaced by BR

reagents: 1)NaOH, Br2 2) H3O+

what is the aldol addition rxn between aldehyde and enolate

where an enolate can attacck aldehyde bc prod has both molecules

reagents: NaOH, H2O

what is the retro aldol reaction

takes prodct from aldol addition to get two ketones

Reagent: NaOH

what is the aldol condensation rxn

add alkene to aldehyde

reagents:[OH-], heat

how do you control a crossed aldol reaction

By using one reactant that has no alpha hydrogens, which forces selectivity in the formation of the aldol product.

what is the claisen condensation rxn

reagents: 1)NaOEt 2) H3O

the alcoxide must match group on reagent

always an ester

what is alklatoin of alpha position rxn

ketone to add alkyl group

reagent:1) LDA 2) alkyl halide that has R group you want

ADDS at less sub position bc of kinetic product being favored

what are the two products of the alklation of the alpha position when the ketone is unsymmetrical

kinetic enolate and thermodynamic enolate

at low temp the kinetic one bc it cannot overcome Ea to be other product