KEMORG2 FINALS REVIEW NAMING AND CONCEPTS

Name

• 1-bromo-2,3-dimethyl-4-hexyne

• 1-bromo-2,3-dimethyl-4-hexene

• 6-bromo-4,5-dimethyl-2-hexyne

• 6-bromo-4,5,-dimethyl-2-hexene

Answer explanation

ALKYNE NAMING:

number to give lower number to substituents (acyclic) or to give lower number to highest priority substituent (in cyclic)

name substituents alphabetically

-yne suffix

Name

• 5-isopropylcyclohexa-1,3-diene

• 5-isopropylcyclohex-1,3-ene

• 4-isopropylcyclohex-1,2-ene

• 4-isopropylcyclohexa-1,2-diene

Answer explanation

ALKENE NAMING

Number to give alkene group lowest numbers

if there are multiple alkenes, it is called a diene

Name

• cis-1-chloro-heptene

• trans-1-chloro-heptene

• E-1-chloro-heptene

• Z-1-chloro-heptene

Answer explanation

ALKENE NAMING

Opposite = E or Trans

Same = Z or Cis

E/Z config is for tri and tetra sub alkenes

cis and trans is for disub

E/Z/Cis/Trans

• E

• Z

• Cis

• Trans

Answer explanation

Z-2-methyl-3-chloro-oct-3-ene

Trisub/Tetrasub = E/Z

di/monosub = Cis or trans

Name

Which of the following will have the highest boiling point

• 
• 
• 

Answer explanation

Bond Strength: alkyne > alkene > alkane

b.p.: alkyne > alkene > alkane

s character: > alkyne > alkene > alkane

all are related since higher s character = higher polarity = higher bp and higher bond strength

Which of the following is the most basic?

• 
• 
• 

Answer explanation

Bond Strength: alkyne > alkene > alkane

b.p.: alkyne > alkene > alkane

s character: > alkyne > alkene > alkane

higher s character = higher acidic character (attracts e- more easily) so lower s character like alkanes are more basic

all are related since higher s character = higher polarity = higher bp and higher bond strength

Why do alkenes / alkynes with bridged ion intermediate mechanisms result in anti additions

• due to polarity

• because the bridged ion acts like a carbonyl group

• due to steric effects

• because the bridged ion acts like an epoxide ring

Answer explanation

recall: epoxide ring opening leads to trans products

epoxides open similar to Sn2 reactions with a backside attack

Activating substituents are ______ while deactivating substituents are ______

• e- donating

  e- donating

• e- withdrawing

  e- withdrawing

• e- donating

  e- withdrawing

• e- withdrawing

  e- donating

Answer explanation

donating electrons makes the benzene pi system more reactive while withdrawing electrons does the opposite. So the more reactive the pi system the faster the rxn (hence activating) vv

Which locations are Ortho with respect to X?

• A

• B

• C

• D

• E

Answer explanation

Ortho is right next beside (1,2)

Meta is adjacent (1,3)

Para is across (1,4)