Chapter 8, Problem 39P

(a)

Interpretation Introduction

Interpretation: The mechanism for formation of product in indicated reaction should be written.

  

Concept introduction:The carbonyl bond is polar with partial positive charge on carbon and partial negative charge on oxygen as illustrated below.

  

Thus it can undergo hydride addition at carbon and proton addition at oxygen. Certain reagents that are useful for such hydride addition at carbonyl carbon include ${\text{NaBH}}_{\text{4}}$ , ${\text{LiAlH}}_{\text{4}}$ . The aluminum and lithium in these reagents such as ${\text{LiAlH}}_{\text{4}}$ tend to push the electron of $\text{Al-H}$ bond towards carbonyl carbon. The work up finally yields alcohol as illustrated below:

  

(b)

Interpretation Introduction

Interpretation:The mechanism for formation of product in indicated reaction should be written.

  

Concept introduction:The carbonyl bond is polar with partial positive charge on carbon and partial negative charge on oxygen as illustrated below.

  

Thus it can undergo hydride addition at carbon and proton addition at oxygen. Certain reagents that are useful for such hydride addition at carbonyl carbon include ${\text{NaBH}}_{\text{4}}$ , ${\text{LiAlH}}_{\text{4}}$ . The aluminum and lithium in these reagents such as ${\text{LiAlH}}_{\text{4}}$ tend to push the electron of $\text{Al-H}$ bond towards carbonyl carbon. The work up finally yields alcohol as illustrated below:

  

(c)

Interpretation Introduction

Interpretation:The mechanism for formation of product in indicated reaction should be written.

  

Concept introduction:The carbonyl bond is polar with partial positive charge on carbon and partial negative charge on oxygen as illustrated below.

  

Thus it can undergo hydride addition at carbon and proton addition at oxygen. Certain regents that are useful for such hydride addition at carbonyl carbon include ${\text{NaBH}}_{\text{4}}$ , ${\text{LiAlH}}_{\text{4}}$ .

(d)

Interpretation Introduction

Interpretation:The mechanism for formation of product in indicated reaction should be written.

  

Concept introduction: The carbonyl bond is polar with partial postive charge on carbon and partial negative charge on oxygen as illustrated below.

  

Thus it can undergo hydride addition at carbon and proton addition at oxygen. Certain reagents that are useful for such hydride addition at carbonyl carbon include ${\text{NaBH}}_{\text{4}}$ , ${\text{LiAlH}}_{\text{4}}$ . The aluminum and lithium in these reagents such as ${\text{LiAlH}}_{\text{4}}$ tend to push the electron of $\text{Al-H}$ bond towards carbonyl carbon.