Activity 4- key - Questions and answers to Prof. Menon\'s Chapter 4 (Steriochemistry) discussion PDF

Preview

Summary

Questions and answers to Prof. Menon's Chapter 4 (Steriochemistry) discussion activity...

Description

February(14,(2017(

1

CHEM211'–Group'activity'#4'-'KEY' ' Name(of(the(student………………………………………………………………….( ( Other(group(members((1)(………………………..(((2)(……………………………(((3)(………………………( (

' 1. Using( Newman( projections,( draw( the( most( stable( conformer( of( 3-methylpentane,( viewed(along(the(C-2—C-3(bond(

(( 2. (a)( Draw( all( the( six( conformers( (staggered( and( eclipsed)( that( result( from( rotation( about( the( C-2—C-3( bond( of( pentane.( ( (b)( Mark( the( most( and( least( stablest( conformations.

( stablest( D( >( (F( and( B)( >( (C( and( E)( >( ( least( stablest( A.( Here( is( a( potential-energy( diagram( for( rotation( about( the( C-2—C-3( bond( of( pentane( through( 360°,( starting( with(the(least(stable(conformer:(

February(14,(2017(

2

( 3. Which( is( the( most( stable( isomer( of! cis-1-bromo-3-methylcyclohexane?(

( Answer:((B)( 4. Draw( the( second( chair( conformer( of( cis-1-tert-butyl-3-methylcyclohexane( by( ring( flipping.((Mark(the(stabler(form.( H

CH3 C CH3

H

CH3 CH3

H H

CH3 C CH3 CH3

CH3

ring flip

H

H CH3

C CH3

more stable less stable cis-1-tert-butyl-3-methylcyclohexane

CH3 CH3

(

February(14,(2017(

3

5. Draw( the( more( stable( conformer( of( cis-1-sec-butyl-4-isopropylcyclohexane.(

( 6. What(are(the(absolute(configurations(of(these(two(molecules?(

( Answer:((B)( (...