Question

Discuss "Alpha Carbon Reactivity" giving at least two examples. Your explanation should include relevant mechanisms and references to actual uses in life

Answer 1

There are many instances of the very term
-carbon
in organic chemistry.The
-carbon
are those carbons which are neighbors of a carbonyl / $-NO_{2}$ / /
-SO,R
groups.So, the reason why
-carbons
are so much recognized in different reactions is because the conjugate base formed due to abstraction of one of the H's from the
-carbon
generates a Conjugate base which is involved in resonance stabilization with these groups itself.Hence,acidity of the H's attached with the
-carbons
are teh principal reason for their increased reactivity.

Some examples of reactions involving such are discussed below-

-carbon

• Aldol Reaction - This reaction is a carbon -carbon bond forming reaction(condensation) using the Enolate anions. This is principally an electrophilic substitution type of raction and two molecules are involved one is the DONOR molecule (which undergoes the
  ahydrogen
  abstraction and the other is the ACCEPTOR molecule where the Conjugate Base (i.e. the Donor attacks) reacts. Basically,the aldol reactions are acid or base catalyzed and the reaction in all the steps are reversible.The stability of the Conjugate Base drive the reaction forward.

HO Nao나 1 . BoloH OH etions Mined Atclo Meac Naoit Ph Ph CH+2Ph ) -

• Alkylation of Enolates- Due to strong Basicity of the Enolate anions,these react with the Alkyl Halides to give
  Sn 2
  or
  E2
  type reactions.

LDA THF Lithiu Diisopotiy 1 Amide LPA E Erglate SN2 Ph BY Ph PL