4. Alkanes and Cycloalkanes

α-Farnesene is a dodecatetraene found in the waxy coating of apple skins. What is its systematic name? Include E and Z where necessary to indicate the configuration of the double bonds.

Draw skeletal structures for each pair of isomers in Problem 7

b.

Why does cis-2-butene have a higher boiling point than trans-2-butene?

Imines can exist as stereoisomers. The isomers are named using the E,Z system of nomenclature (Section 4.2 ). The lone pair has the lowest priority.

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Draw the structure of each of the following compounds:

a. the (E)-hydrazone of benzaldehyde

b. the (Z)-oxime of propiophenone

Draw and name all stereoisomers of 3-chlorohepta-2,4-diene

a. using the cis-trans nomenclature.

Which of the following cycloalkanes are capable of geometric (cis-trans) isomerism? Draw the cis and trans isomers.

a. 3-ethyl-1,1-dimethylcyclohexane

Which of the following cycloalkanes are capable of geometric (cis-trans) isomerism? Draw the cis and trans isomers.

c. 1-ethyl-3-methylcyclopentane

Draw a structure for each compound (includes old and new names).

d. 1,3-cyclohexadiene

e. cycloocta-1,4-diene

f. (Z)-3-methyl-2-octene

Determine which compounds show cis-trans isomerism. Draw and label the isomers, using both the cis-trans and E-Z nomenclatures where applicable.

a. pent-1-ene

b. pent-2-ene

Which of the following cycloalkanes are capable of geometric (cis-trans) isomerism? Draw the cis and trans isomers.

b. 1-ethyl-3-methylcycloheptane

Draw the molecular orbital picture of trans-but-2-ene.

Draw skeletal structures for the compounds in Problem 3, including any cis–trans isomers.

1.

Draw skeletal structures for the compounds in Problem 3, including any cis–trans isomers.

2.

a. Draw the condensed structures and give the systematic names for all the alkenes with molecular formula C₆H₁₂, ignoring stereoisomers. (Hint: There are 13.)

b. Which of the alkenes have E and Z isomers?

c. Which of the alkenes is the most stable?

d. Which of the alkenes is the least stable?

For those compounds that can exist as cis and trans isomers, draw and label the isomers.

1.

2.