Chapter 7.3, Problem 4P

Interpretation Introduction

Interpretation:

The number of alkenes having the molecular formula ${\text{C}}_{\text{5}}{\text{H}}_{\text{10}}$ is to be determined. Their structures and their IUPAC names are to be written. The configuration of stereoisomers as cis or trans is to be specified.

Concept Introduction:

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The alkene corresponding to the longest continuous chain that includes the double bond is considered as the parent, and the chain is numbered in the direction in which doubly bonded carbons get lower numbers. The suffix $-ene$ is used to indicate the presence of a double bond.

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The position of the double bond is indicated by writing the smaller number in the name out of the two double bonded carbon atoms.

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Cis and trans stereoisomers are possible only when the double bond is not a terminal double bond.

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When two similar groups are present on the same side of the double bond, the isomer is a cis isomer. If the similar groups are on the opposite sides, the isomer is a trans isomer.