Alkynes Knowledge-Based Download PDF

Questions

1. 1.

   Which of the following compounds is the major organic product formed when pent-1-yne is treated with disiamylborane, followed by basic hydrogen peroxide ($\text{H}_2\text{O}_2$, $\text{NaOH}$)?

   • A) Pentanal
   • B) Pentan-2-one
   • C) Pentanoic acid
   • D) Pentan-1-ol
2. 2.

   Which of the following compounds is the major organic product formed when propyne is treated with sodium amide ($\text{NaNH}_2$) in liquid ammonia, followed by the addition of bromoethane?

   • A) Pent-2-yne
   • B) Pent-1-yne
   • C) But-2-yne
   • D) Hex-3-yne
3. 3.

   Which of the following compounds is the major organic product formed when but-1-yne reacts with two molar equivalents of hydrogen bromide (HBr)?

   • A) 2,2-dibromobutane
   • B) 1,2-dibromobutane
   • C) 1,1-dibromobutane
   • D) 2,3-dibromobutane
4. 4.

   Which of the following reagents or reaction conditions converts but-2-yne stereoselectively into (E)-but-2-ene?

   • A) $\text{H}_2$ in the presence of Lindlar's catalyst
   • B) $\text{Na}$ in liquid $\text{NH}_3$
   • C) $\text{H}_2$ in the presence of a $\text{Pt}$ catalyst
   • D) $\text{HCl}$ in the presence of organic peroxides
5. 5.

   Which of the following compounds is the major organic product formed when propyne undergoes acid-catalyzed hydration in the presence of mercury(II) sulfate?

   • A) Propanal
   • B) Propanoic acid
   • C) 1-Propanol
   • D) Propanone