Chap 5 Isomers

Question 1

Define the following?

1. Chiral
2. Enantiomer
3. Chiral
4. Racemic Mixture
5. Achiral
6. Meso compound
7. Diastereomers

Answer 1

Question 2

Define

1. Isomer?
2. Constitutional isomer?
3. Stereoisomers?
4. Enantiomer?
5. Diastereomers

Answer 2

1. Isomer= Same cooking formula but cooked(bonded) differently.
2. Constitutional isomers= Diff countries have Diff Constituiutional $Bond (connectivity)
3. Enantiomers= The Enan Twin ( Mirror Image)
4. Diasteromers= Non Identical twins

Question 3

What is the R,S configuration for

1. Identical
2. Enantiomers
3. Diastereomers

Answer 3

1. R&S match exactly
2. R&S opposite
3. If one chiral center in the same configuration and one in the opposite (ex-RR,RS)

Question 4

Chiral compounds have ______ mirror images called ______.

Answer 4

Question 5

Enantiomers have many of the same _____ properties, they are ?

Answer 5

Enantiomers have many of the same physical properties: b.p., m.p., polarity, etc.

Question 6

Chiral compounds are said to be ______ as they rotate plane-polarized light.
A racemic mixture is a 50/50 mixture of _______and is optical______.

Answer 6

Question 7

Achiral compounds are ______ with their mirror images.

Achiral compounds are optical______ as they do not rotate plane-polarized light.

Answer 7

Question 8

Compounds with Multiple Chiral Centers 2n =

Answer 8

Question 9

• *Diastereomers** - non-________, ______images
• molecules with some _____centers in the same and some in _____configurations -_______ isomers are diastereomers

Answer 9

Question 10

Meso compounds – 1)____ but 2) having ______ centers

Answer 10

Meso compounds – 1) achiral but 2) having chiral centers

Question 11

Diastereomers have ___ than___ chiral centers.

Answer 11

Question 12

Amines are ____ because they interconvert.

Answer 12

Question 13

Chiral compounds are defined as those that have ______ ,_____images

They are optical _____ have an ______, and usually have at least one asymmetric center (there are a couple exceptions).

Meso compounds are ______ so a compound that is ____cannot be a meso compound.

Answer 13

An asymmetric carbon atom is a carbon atom that is attached to four different types of atoms or groups of atoms

Question 14

If a structure has alkene that is capable of cis-trans isomerism, does that count as a stereocenter?

Answer 14

or 2^3=8 ( because 3 stereocenters)

Question 15

If a structure has the same number of carbon but different numbers of hydrogen atoms, is the structure identical?

Answer 15

NO!

Question 16

Define Enantiomer?

Answer 16

enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable, much as one’s left and right hands are mirror images of each other that cannot appear identical simply by reorientation.

Question 17

2 chiral centers both of which are in opposite configurations which makes them ______?

Answer 17

2 chiral centers both of which are in opposite configurations which makes them enantiomers

Question 18

A double bond on a structure is not free to rotate and therefore these structures are not ____. They are cis-trans isomers which are _____(_____,______ images).

Answer 18

A double bond is not free to rotate and therefore these structures are not identical. They are cis-trans isomers which are diastereomers (non-superimposable non-mirror images).

Question 19

A structure with the same formula can be isomers or identical. if their ‘bond connectivity’ is very different making them _____ (a.k.a _______).

Answer 19

same formula (C6H15N) so they are isomers or identical. They are obviously not identical and their ‘bond connectivity’ is very different making them structural isomers (a.k.a constitutional isomers).

Question 20

Fisher projection that has 2 chiral centers one of which is in the same configuration and one in the opposite configuration, makes them?

Answer 20

diastereomers (non-superimposable non-mirror images).

Question 21

Fisher projection with3 chiral centers all of which are in the opposite configuration make it?

Answer 21

enantiomers (non-superimposable mirror images).