Chapter 3 review notes PDF

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Chapter 3 review...

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Chapter(4:(Alkanes(and(Cycloalkanes( Question)1.) ) Draw% ALL) possible%constitutional) isomers%(do% not% include% stereoisomers)% of% structures% with% the% molecular%formula%C3H5ClO%that%are:%% % (a) Aldehyde%or%ketone%compounds% % % % % % % % % (b) Acid%halide%compounds% % % % % % % % % (c) Cyclic%ethers%with%oxygen%within%a%ring% % % % % % % % % (d) Cyclopropane%ring%containing%an%alcohol% % %

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Question)2.) Draw% ALL) possible%constitutional) isomers%(do% not% include% stereoisomers)% of% structures% with% the% molecular%formula%C3H6O2%that%are:% (a) Carboxylic%acids%or%carboxylic%acid%derivatives:% % % % % (b) Ketones%or%Aldehydes:% % % % % % % (c) Three-membered%rings%(containing%only%carbon%within%the%ring):% % % % % (d) Three-membered%cyclic%ethers%(containing%oxygen%in%the%ring):% )

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Question)3.) (a) Draw% ALL% the%constitutional)isomers% of% structure% C3H7N%that% do) not% contain% a% ring.% For% each% isomer,%also%indicate%whether%each%it%is%primary,%secondary%or%tertiary.% % % % % % % % % % % % (b) Draw% the% structure(s)% that% can% exist% as% more% than% one% isomer,%but%where% the% isomers% are% NOT) constitutional:% #

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Question)4.) Given% the%molecules%below,%complete%the%Newman%projections%on%the%right%utilizing%the%criteria%listed% below%each%template.%A%methyl%group%has%been%placed%on%the%front%carbon%to%get%you%started.%(Hint:%Br% has%a%larger%atomic%radius%then%CH3)% %

(a)%

%

(b)%

% % %

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Question)5.) ) (a) On% the% template% below,% draw% the% structure% of% 1,3-dimethyl-4,6-diethyl-1-propyl-cyclohexane.% Be% sure%to%place%carbons%1%and%2%where%indicated,%but%do%not%worry%about%stereochemistry%or%showing% hydrogen%atoms%for%this%structure.% %

1

2 %

% (b) On%the%template%below,%complete%the%structure%to%show%the%MOST)STABLE%CHAIR%conformation% of% 1,3-dimethyl-4,6-diethyl-1-propyl-cyclohexane.%Be%sure%to%place% carbons%1%and% 2%where%indicated% and%showing%ALL%hydrogen%atoms%for%this%structure.% % %

2

1 %

% (c) Complete%the%following%template%to%show%the%BOAT%conformation%of%the%structure%shown%in%Part%(b).% % %

2

1 %

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(d) Which%non-hydrogen%substituents%exhibit% eclipsing)interactions% in%the%boat%you%drew%in% Part%(c)?% If%none,%clearly%state%“NONE”.% % % % % % % (e) Which%non-hydrogen%substituents%exhibit%flagpole)interactions%in%the%boat%you%drew%in%Part%(c)?%If% none,%clearly%state%“NONE”.% ) )

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Question)6.) % (a) On%the%template%below,%draw%the%structure%of%1-chloro-2,3-diethyl-5-methyl-cyclohexane.%Be%sure%to% place% carbons% 1% and% 2% where% indicated,% but% do% not% worry% about% stereochemistry% or% showing% hydrogen%atoms%for%this%structure.% %

1

2 %

% (b) On%the%template%below,%complete%the%structure%to%show%the% MOST)STABLE%CHAIR%conformation% of% 1-chloro-2,3-diethyl-5-methyl-cyclohexane.%Be%sure%to%place%carbons%1%and%2%where%indicated%and% showing%ALL%hydrogen%atoms%for%this%structure.% % %

2

1 %

% (c) Complete%the%following%template%to%show%the%BOAT%conformation%of%the%structure%shown%in%Part% (b).% % %

2

1 %

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(d) Which%substituents%exhibit%flagpole)interactions%in%the%boat%you%drew%in%Part%(c)?%Be%sure%to%include% hydrogens%in%your%analysis.%If%none,%clearly%state%“NONE”.% % !

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Question)7.% % Answer%the%following%questions%about%3,4-dimethylhexane:% % (a) How%many%stereoisomers%exist?%_____________%% % (b) Complete% the% following% Newman% projection% along% the% C3−C4% bond% to% show% the% LEAST) stable) ECLIPSED%conformation%of%the%meso%isomer.% % %

H

% % % (c) Complete% the% following% Newman% projection% along% the% C3−C4% bond% to% show% the% MOST) stable% STAGGERED%conformation%of%the%meso%isomer.%% % %

H

% % % (d) Complete%the%template%below%to%show%the%LOWEST)ENERGY%conformer%of% another%diastereomer% for%this%compound.%% % %

H % % (e) Which%isomer%is%the%MOST%stable?% % Part)(c))Meso)Compound) Part)(d))Diastereomer)

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Parts)(c)/(d))are)equally)stable)

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Question)8.% Answer%the%following%questions%about%3,4-ditert-butyl-hexane:% % (a) Complete% the% following% Newman% projection% along% the% C3−C4% bond% of% (3S,4S)-3,4-ditert-butylhexane%to%show%the%MOST)stable%conformation.% %

H

% % (b) Complete% the% following% Newman% projection% along% the% C3−C4% bond% of% (3S,4R)-3,4-ditert-butylhexane%to%show%the%MOST)stable%conformation.% %

H

% % (c) Complete%the%following%table%to%show%the%NUMBER% of%relevant%gauche%interactions% present%within% these%stereoisomers:% % %

tBu-Et%

% (3S,4S)% % % (3S,4R)% %

Et-Et%

tBu-H%

Et-H%

H-H%

% %

%

%

%

%

% %

%

%

%

%

% % (d) Based%on%your%answer%to%Part%(c),%CIRCLE%which%of%the%two%stereoisomers%is%MOST%stable:% % (3S,4S)) ) PRACTICE'QS#

(3S,4R))

Both)are)equal)

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Question)9.) Although%chlorine%is%larger%than%carbon,%it%is%actually%smaller%than%a%methyl%group%as%it%lacks%the%presence% of%any%hydrogen%atoms.%Given%this%information:% (a) Complete%the%following%Newman%projection%along%the%C2−C3%bond%of%2,3-dichlorobutane%to%show% the%MOST%stable%conformation%of%the%MOST%stable%isomer.% % %

Cl Me

H

%

% % (b) Complete%the%following%Newman%projection%along%the%C2−C3%bond% of%2,3-dichlorobutane%to%show% the%LEAST)stable%conformation%of%the%LEAST)stable%isomer.% % %

Cl H

Me %

% % (c) Indicate%the%absolute%configuration%of%the%front%and%back%carbon%atoms,%respectively,%in%the%Newman% projection%you%have%drawn%in%Part%(a):% % R)and)R)

S)and)R)

R#and)S)

S)and)S)

% % (d) CIRCLE%which%term%describes%the%MOST%stable%isomer.% % CHIRAL)

MESO)

RACEMIC)

% % PRACTICE'QS#

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(e) Complete%the%following%Newman%projection%along%the%C2−C3%bond%of%2,3-dichlorobutane%to%show% the%MOST%stable%conformation%of%the%other%diastereomer)of%the%structure%in%Part%(a).) % %

Cl H

Me )

) ) % % % % % % % % % % % % % % % % % % % % PRACTICE'QS#

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