Prochirality

Question 1

What is prochirality?

Answer 1

• function of the fact that you have a chiral catalyst acting on a substrate
• ‘fake chirality’

Question 2

1st type of prochirality

Answer 2

2 chemically identical atoms (often H) or groups, located on a tetrahedral center (sp3)
- geometrically distinct, which is what forms pro-R/s
- bc not rlly R or S due to same groups, but they are interacting with a chiral catalyst
- recognizes these as separately/distinct even though occupied by same atom/group

Question 3

CHemically equivalent groups

Answer 3

leucine, valine side chains (2 Me groups)

Question 4

draw a pro-chiral atom, R and S

Answer 4

one of the identical atoms in middle, the rest surrounding.

Question 5

enantiotopic

Answer 5

no fixed chiral center present

Question 6

diastereotopic

Answer 6

already have a fixed chiral center present

Question 7

Are the H in CH2 of Tyr enantiotopic or diastereotopic

Answer 7

diastereotopic, because the alpha C is chiral

Question 8

2nd type of prochiral molecule

Answer 8

planar molecules (sp2 hybridized face)
- no rotational symmetry, cannot rotate into self
- two distinct faces (re and si)

Question 9

How to identify Re vs Si

Answer 9

Re = clockwise

Si = counterclockwise