Chapter 16, Problem 68IP

 (a)

Interpretation Introduction

Interpretation:

For the given data’s of $\text{α-terpinene}$, the number of double bonds presented, the structure and the value of ${\text{λ}}_{\text{max}}$ are needed to be determined.

Concept introduction:

• The Hydrogen Deficiency Index (HDI): It is used to measure the number of degrees of unsaturation (double and triple bonds or ring) present in a given molecule. It is determined by using the formula. $\begin{array}{l}\text{HDI}\text{=}\frac{\text{1}}{\text{2}}\text{[(2}\times \text{No}\text{. of Carbon atoms)+2+(No}\text{. of Nitrogen atoms)}\\ \text{ - (No}\text{. of Hydrogen atoms)-(No}\text{. of halogens)]}\end{array}$
• Ozonolysis Reaction: It is an oxidative reaction which is used to oxidize the $\text{C=C}$ bonds to $\text{2}\text{C=O bonds}$.
• The π-systems of conjugated dienes absorb UV or visible light (200nm – 800nm).
• The wavelength of maximum absorption of a compound is called ${\text{λ}}_{\text{max}}$.
• According to Woodward-Fieser rule, the portion of the molecule which absorbs UV-visible light is called chromophore and the groups attached to the chromophore are auxochromes. Woodward-Fieser rule gives the estimate value for ${\text{λ}}_{\text{max}}$.
• The estimate value for ${\text{λ}}_{\text{max}}$ are given in below table,

FEATURES	${\text{λ}}_{\text{max}}$- value	Example	Calculation
Conjugated- diene	Base value     = 217		217 nm
Each additional double bond	+30		Base: 217 $+2\times 30$
Each auxochromic alkyl group	+5		Base: 217                   $+3\times 5$
Each exocyclic double bond	+5		Base: 217      + 5
Homoannular diene (both double bonds are situated in a ring)	+ 39		Base: 217     +39

(b)

Interpretation Introduction

Interpretation:

For the given data’s of $\text{α-terpinene}$, the number of double bonds presented, the structure and the value of ${\text{λ}}_{\text{max}}$ are needed to be determined.

Concept introduction:

• The Hydrogen Deficiency Index (HDI): It is used to measure the number of degrees of unsaturation (double and triple bonds or ring) present in a given molecule. It is determined by using the formula. $\begin{array}{l}\text{HDI}\text{=}\frac{\text{1}}{\text{2}}\text{[(2}\times \text{No}\text{. of Carbon atoms)+2+(No}\text{. of Nitrogen atoms)}\\ \text{ - (No}\text{. of Hydrogen atoms)-(No}\text{. of halogens)]}\end{array}$
• Ozonolysis Reaction: It is an oxidative reaction which is used to oxidize the $\text{C=C}$ bonds to $\text{2}\text{C=O bonds}$.
• The π-systems of conjugated dienes absorb UV or visible light (200nm – 800nm).
• The wavelength of maximum absorption of a compound is called ${\text{λ}}_{\text{max}}$.
• According to Woodward-Fieser rule, the portion of the molecule which absorbs UV-visible light is called chromophore and the groups attached to the chromophore are auxochromes. Woodward-Fieser rule gives the estimate value for ${\text{λ}}_{\text{max}}$.
• The estimate value for ${\text{λ}}_{\text{max}}$ are given in below table,

FEATURES	${\text{λ}}_{\text{max}}$- value	Example	Calculation
Conjugated- diene	Base value     = 217		217 nm
Each additional double bond	+30		Base: 217 $+2\times 30$
Each auxochromic alkyl group	+5		Base: 217                   $+3\times 5$
Each exocyclic double bond	+5		Base: 217      + 5
Homoannular diene (both double bonds are situated in a ring)	+ 39		Base: 217     +39

(c)

Interpretation Introduction

Interpretation:

For the given data’s of $\text{α-terpinene}$, the number of double bonds presented, the structure and the value of ${\text{λ}}_{\text{max}}$ are needed to be determined.

Concept introduction:

• The Hydrogen Deficiency Index (HDI): It is used to measure the number of degrees of unsaturation (double and triple bonds or ring) present in a given molecule. It is determined by using the formula. $\begin{array}{l}\text{HDI}\text{=}\frac{\text{1}}{\text{2}}\text{[(2}\times \text{No}\text{. of Carbon atoms)+2+(No}\text{. of Nitrogen atoms)}\\ \text{ - (No}\text{. of Hydrogen atoms)-(No}\text{. of halogens)]}\end{array}$
• Ozonolysis Reaction: It is an oxidative reaction which is used to oxidize the $\text{C=C}$ bonds to $\text{2}\text{C=O bonds}$.
• The π-systems of conjugated dienes absorb UV or visible light (200nm – 800nm).
• The wavelength of maximum absorption of a compound is called ${\text{λ}}_{\text{max}}$.
• According to Woodward-Fieser rule, the portion of the molecule which absorbs UV-visible light is called chromophore and the groups attached to the chromophore are auxochromes. Woodward-Fieser rule gives the estimate value for ${\text{λ}}_{\text{max}}$.
• The estimate value for ${\text{λ}}_{\text{max}}$ are given in below table,

FEATURES	${\text{λ}}_{\text{max}}$- value	Example	Calculation
Conjugated- diene	Base value     = 217		217 nm
Each additional double bond	+30		Base: 217 $+2\times 30$
Each auxochromic alkyl group	+5		Base: 217                   $+3\times 5$
Each exocyclic double bond	+5		Base: 217      + 5
Homoannular diene (both double bonds are situated in a ring)	+ 39		Base: 217     +39