Question

Assume general laboratory reagents are available at your disposal and that multiple steps may be needed:
Which of the following sequence(s) helps convert styrene to 2-phenylacetaldehyde?

• A. Hybroboration oxidation; followed by Oxidation by PCC
• B. 1. $B{r}_2/C{H}_{2}C{l}_2$; 2. $Et{O}^{-}/EtOH$ 3. $Si{a}_{2}BH$, followed by $H_2{O}_2,O{H}^{-}$
• C. Both a and b
• D. Neither a nor b

Answer 1

The correct option is C Both a and b


Alternatively:

With a terminal alkyne, a bulky dialkyl borane like disiamylborane gives an enol that tautomerizes
into the required product: