chem exam 3 (enantiomers/diastereomers))

Enantiomers

non-superimposeable mirror images (non-geometric)

to draw an enantiomer

switch groups on both compounds

Diastereomers

non-superimposable

no mirror images

must have at least two chiral centers

at least one same (S,S); at least one diff (S,R)

to draw a diasteromer

keep one compound the same & switch groups on other compound

Chiral Centers

sp3 carbon

4 unique groups

Absolute Configuration

clockwise: R

counterclockwise: S

Lowest Priority

back (keep same)

front (flip answer)

in plane (use paper method w/ lowest farthest from me)

meso compound

have to be R & S

even amount of chiral centers?

are they attached to the same thing?

internal mirror image

chiral

can be even or odd #

chiral=enantiomer

achiral

no chiral center

superimposable

deciding relationships

1. molecular formula

2. connectivity (name)

3. differ across ridgid plane

4. chiral center # (same chiral centers=identical)

identical compound

same molecular formula, same connectivity, superimposable