Chapter 10.8, Problem 12E

Interpretation Introduction

Interpretation:Structure of $\left(\text{+}\right)\text{-}\alpha \text{-naphthylurethane}$ of $(–)\text{-isopinocampheol}$ should be written.

Concept introduction:Hydroboration-oxidation involves a sequence of two reactions. The hydroboration stage involves the treatment of alkene with diborane that generates alkyl borane. In second stage hydrogen peroxide in alkaline medium is used to oxidize the alkyl borane produced in step 1 that leads to the synthesis of alcohols from alkenes.

Hydroboration of $\left(\text{+}\right)\text{-}\alpha \text{-Pinene}$ occurs as illustrated as below.

  

Since structure I have ${\text{BH}}_2$ added from backside so stereospecific nature of syn addition reaction suggests that $\text{OH}$ must add from the same backside as the side of ${\text{BH}}_2$ to result in exclusive syn product II.