Question

Which sequence of steps describes the best synthesis of $2-methyl-3-pentanone$?

• A. (1) $1-$Propanol $+(C{H}_3{)}_{2}CHMgBr$, diethyl ether
  (2) $H_3{O}^{+}$
  (3) $PCC,C{H}_{2}C{l}_2$
• B. (1) $1-$Propanol $+N{a}_{2}C{r}_2{O}_7,H_{2}S{O}_4,H_{2}O$ heat
  (2) $SOC{l}_2$
  (3) $(C{H}_3{)}_{2}CHCl,AlC{l}_3$
• C. (1) $1-$Propanol $+PCC,C{H}_{2}C{l}_2$
  (2) $(C{H}_3{)}_{2}CHLi$, diethyl ether
  (3) $H_3{O}^{+}$
  (4) $N{a}_{2}C{r}_2{O}_7,H_{2}S{O}_4,H_{2}O$ heat
• D. (1) $2-$Propanol $+N{a}_{2}C{r}_2{O}_7,H_{2}S{O}_4,H_{2}O$, heat
  (2) $C{H}_{3}C{H}_{2}C{H}_{2}Li$, diethyl ether
  (3) $H_3{O}^{+}$
  (4) $PCC,C{H}_{2}C{l}_2$

Answer 1

The correct option is C (1) $1-$Propanol $+PCC,C{H}_{2}C{l}_2$

(2) $(C{H}_3{)}_{2}CHLi$, diethyl ether
(3) $H_3{O}^{+}$
(4) $N{a}_{2}C{r}_2{O}_7,H_{2}S{O}_4,H_{2}O$ heat
Alcohols are oxidized to carbonyl compounds in presence of PCC. Alcohols can be oxidized to carbonyl compounds in presence of $N{a}_{2}C{r}_2{O}_7/H^{+}$.