Ch. 25: Amino Acids

Question 1

What do amino acids have to be stained with?

Answer 1

Ninhydrin, NaOH (creates purple stain)

Question 2

Synthesis of AA via alpha-haloacid (from carboxylic acid)

Answer 2

1. Br2, PBr3 2. H2O 3. XS NH3, SN2

Question 3

Syntheis of AA via amidomalonate synthesis (from double ester)

Answer 3

1. NaOEt 2. RX 3. H3O+, heat

Question 4

Synthesis of AA via strecker synthesis (from aldehyde)

Answer 4

1. NH4Cl, NaCN 2. H3O+

Question 5

Enantioselective Synthesis (from carboxylic acid w/ NHAc)

Answer 5

1. H2, BINAP 2. NaOH, H2O 3. H3O+

Question 6

Edman Degradation (AA w/ peptide)

Answer 6

1. Ph-N=C=S 2. CF3CO3H
   (yields peptide w/ NH2)

Question 7

Peptide bond formation

Answer 7

DCC

Question 8

Protecting group for N-terminus (NH2)

Answer 8

Boc2O (Adds Boc to NH2)

Question 9

Removal of N-protecting group

Answer 9

CF3COOH

Question 10

Protecting group for C-terminus (COOH)

Answer 10

[H+], ROH

Question 11

Removal of C-protecting group

Answer 11

NaOH, H2O