Level 189 Level 191
Level 190

Organic Chemistry: Optical


57 words 0 ignored

Ready to learn       Ready to review

Ignore words

Check the boxes below to ignore/unignore words, then click save at the bottom. Ignored words will never appear in any learning session.

All None

Ignore?
chiral
due to this interconversion, alkyl amines are not
Achiral
doesn't have 4 different substituents
Enantiomer
An optical isomer
R configuration
goes to right (highest to lowest)
S configuration
goes to left (highest to lowest)
meso
molecule is achiral
raecimic mixture
50/50 mix of enantiomers
diasteomers
stereoisomers that
2^n
equation for max number of stereoisomers
isomers
compounds that have same formula but different structures
constitutional isomers
compounds that have the same molecular formula and different connectivity
stereoisomers
isomers with same connectivity but different orientation of atoms in space
plane of symmetry
imaginary plane passing through an object dividing it so that one half is the mirror image of the other half
center of symmetry
Point so situated that identical components of the object are located on opposite sides and equidistant from that point along any axis passing through it.
Common cause of chirality
tetrahedral atom; carbon bonded to four different groups
chiral center
a carbon atom with four different atoms or groups of atoms bonded to it
Enantiomers
A substrate with a single chirality center at the carbon attached to the leaving group will give rise to a pair of _______
Priority rule (atomic #)
Each atom bonded to the chiral center is assigned a priority based on atomic number; the higher the atomic number the higher the priority
Priority rule (point of difference)
If priority cannot be assigned per the atoms bonded to the chiral center, look to the next set of atoms; priority is assigned at the first point of difference
Priority rule (bonds)
Atoms participating in a double or tiple bond are considered to be bonded to an equivalent number of similar atoms by single bonds
Naming chiral centers
Locate the chiral center and identify four substituents; assign priority from 1 to 4 to each substituent; orient the molecule so that the group of lowest priority is directed away from you. Read the t…
# of stereoisomers possible
2^(# of chiral centers). For example, molecule with 2 chiral centers has 4 stereoisomers
Erythrose
A pair of cis enantiomers
Threose
A pair of trans enantiomers
diastereomers
two or more chiral centers
Meso compound
achiral compound that contains more than one chiral center---> internal plane of symmetry
Ordinary light
light oscillating in all planes perpendicular to its direction of propagation
plane-polarized light
light oscillating only in parallel planes; vector sum of left and right circularly polarized light
Optically active
Affects light
Circularly polarized light
interacts one way with an R chiral center, and the opposite way with its enantiomer
rotation of the plane of polarization
interaction of PP light with chiral compound..
polarimeter
device for measuring the extent of rotation of plane polarized light
observed rotation
the number of degrees (alpha) through which a compound rotates the plane of polarized light
dextrorotatory
refers to a compound that rotates the plane of polarized light to the right
levorotatory
refers to a compound that rotates the plane of polarized light to the left
specific rotation
Memorize the formula for
Racemic mixture
(Gr. bunch of grapes) equimolar mixture of two enatniomers; contains equal dextrorotatory and levorotatory molecules; specific rotation 0.
Resolution
the separation of a racemic mixture into its enantiomers
Enzyme-substrate
Substrate fits into binding site on enzyme surface
Enantiomers, chiral environment
different physiological properties; right handed molecule in right handed binding site
(S) Ketamine vs (R) ketamine
they are enantiomers; however have different medicinal effects. (S) ketamine is an anesthesia with 4X the affinity for the PCP site, more potent analgesic does not lower BP or respiration. (R) ketamine is a hallucin…
Amino acid
20 most common have a central carbon (alpha carbon) bonded to an NH2 group and COOH group; In 19 of 20 C is chiral center. R is a functional group that determines the amino acid.
Zwitterion
the H of the COOH group attaches to the NH2 group (forming COO- and NH3+)
Amino acid (S&R configuration)
18 of the 19 alpha carbons have the R configuration, while one has S.
Amino acid pH
at neutral pH, an amino acid exists an internal salt
Optical activity
Ability of a chiral substance to rotate plane polarized light.
Angle of rotation
How much a chiral subtance rotates light.
They have the exact same enantioners
If a substance has the exact same angle of rotation as another substance.
IN naming chiral carbons
It is important to use wedge and dash.
Firs step in naming chiral carbons
Prioritize the groups in terbs of atominc number.
Choose the Right
R means the clock rotates to the right.
So stupid = S.
The stupid way is the way the clock doesnt rotate.
Chiral carbon
A carbon with 4 different groups.
To orient the way the priority numbers rotate
you must have the lowest priority going in to the plane of the paper
If there are 2 chiral carbons
You name both of them and write which way they rotate and put it on the outside.
Fischer projections
I dont understand this concept
What are prochiral molecules
Before reactions do not have chiral carbons, but after do.