Exam 3 Material

Orgo Final

II

II and IV

(a)SOCl₂/80⁰C, (b)2 equv.CH₃CH₂MgBr, (c)H₃O⁺.

C only

II

3, 4, 1, 2

I

(a)Mg,(b)CO₂, (c)H₃O⁺, (d)SOCl₂, (e) 2NH(CH₃)₂, (f)LiAlH₄, (g)H₃O⁺.

can change

II

III

First structure: Racemization does not occur because the chirality center, while alpha to the carbonyl group, does not have an acidic hydrogen. Second structure: Racemization does not occur because the chirality center, while alpha to the carbonyl group, does not have an acidic hydrogen. Third structure: Racemization occurs because the chirality center has an acidic alpha-hydrogen. This hydrogen is removed upon enol (in acid) or enolate ion (in base) formation. Protonation of the enol (enolate ion) to regenerate the ketone then occurs on either side of the trigonal-planar alpha carbon resulting in racemization.

IV

II

III

II reacting with IV

IV

II

II

I

I

CH₃OH/H⁺/heat

III

II

Method III

B

C

III

4, 3, 1, 2

IV

III

II

III

I reacting with VI

IV

II

II

No reaction

I

I, III, IV

II

IV

A

IV

B

I

II and IV

3, 4, 1, 2

B only

II

II

II

(a)CH₃O^-, (b)CH₃CH₂I.