Chapter 26, Problem 55IP

(a)

Interpretation Introduction

Interpretation:

Limonene is a monoterpene or diterpene has to be found out and the products obtained when limonene is treated with excess hydrogen bromide and when it is treated with ozone need to be drawn.

Concept introduction:

Terpenes are naturally occurring compounds which share a common feature. All terpenes are thought to be assembled from isoprene units having five carbon atoms.  So the structure of terpenes has the carbon atoms in multiples of five only.

Terpenes can be classified based on the carbon atoms present in it and a few is listed below,

• 10 carbon atoms - monoterpene
• 15 carbon atoms - sesquiterpene
• 20 carbon atoms - diterpene

To find: whether limonene is a monoterpene or diterpene.

(b)

Interpretation Introduction

Concept introduction:

When an alkene is treated with excess hydrogen bromide bromination takes place in an electrophilic addition fashion according to markownikoff’s rule to form the respective product.

To draw: the structure of product obtained when limonene is treated with excess hydrogen bromide and find whether the product is chiral or not.

(c)

Interpretation Introduction

Concept introduction:

Ozonolysis of the an alkene by use of ozone yields two aldehyde. The carbon-carbon double bond is broken and aldehyde is formed.

To draw: the structure of product obtained when limonene is treated with ozone followed by DMS