Chapter 9.5, Problem 9CC

(a)

Interpretation Introduction

Interpretation:

To predict the major products for the given alkyne reaction and transformations should be identified.

Concept Introduction:

Hydrogenation:  The hydrogenation is a reduction reaction which results in an addition of hydrogen. Several organic compounds (alkenes, alkynes) is hydrogenated, it becomes more saturated.

Hydrogen reduction reaction: The alkenes or alkynes can be reduced to alkanes with ${\text{H}}_{\text{2}}$ in the presence of metal catalyst $\left(\text{Pd, Pt, Ni}\right)$. The new $\text{C-H σ}$ bonds are formed simultaneously from $\text{H}$ atoms absorbed into the metal surface.

Platinum reduction reaction: The alkenes can be reduced to alkanes with ${\text{H}}_{\text{2}}$ in the presence of metal catalyst $\left(\text{Pt}\right)$. The two new $\text{C-H σ}$ bonds are formed simultaneously from $\text{H}$ atoms absorbed into the metal surface. This type of reaction stereospecific giving only the cis (syn) addition product.

(b)

Interpretation Introduction

Interpretation:

To predict the major products for the given alkyne reaction and transformations should be identified.

Concept Introduction:

Hydrogenation:  The hydrogenation is a reduction reaction which results in an addition of hydrogen. Several organic compounds (alkenes, alkynes) is hydrogenated, it becomes more saturated.

Hydrogen reduction reaction: The alkenes or alkynes can be reduced to alkanes with ${\text{H}}_{\text{2}}$ in the presence of metal catalyst $\left(\text{Pd, Pt, Ni}\right)$. The new $\text{C-H σ}$ bonds are formed simultaneously from $\text{H}$ atoms absorbed into the metal surface.

Platinum reduction reaction: The alkenes can be reduced to alkanes with ${\text{H}}_{\text{2}}$ in the presence of metal catalyst $\left(\text{Pt}\right)$. The two new $\text{C-H σ}$ bonds are formed simultaneously from $\text{H}$ atoms absorbed into the metal surface. This type of reaction stereospecific giving only the cis (syn) addition product.