question_answer

Consider the following conversion:

Which of the following sets of reagents, would successfully accomplish the conversion shown?

A) \[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}MgBr;{{H}_{3}}{{O}^{+}};PCC,C{{H}_{2}}C{{l}_{2}}\]

B) \[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}MgBr;{{H}_{3}}{{O}^{+}};{{H}_{2}}S{{O}_{4}},\text{heat};PCC,C{{H}_{2}}C{{l}_{2}}\]

C) \[{{({{C}_{6}}{{H}_{5}})}_{3}}\overset{+}{\mathop{P}}\,-\overset{-}{\mathop{\overset{\bullet \bullet }{\mathop{C}}\,}}\,HC{{H}_{2}}C{{H}_{3}};{{B}_{2}}{{H}_{6}};{{H}_{2}}{{O}_{2}},H{{O}^{-}}\]

D) \[{{({{C}_{6}}{{H}_{5}})}_{3}}\overset{+}{\mathop{P}}\,-\overset{-}{\mathop{\overset{\bullet \bullet }{\mathop{C}}\,}}\,HC{{H}_{2}}C{{H}_{3}};{{H}_{2}}S{{O}_{4}};{{H}_{2}}O\]

Correct Answer: C

Solution :

Carbonyl compounds reacts with \[({{C}_{6}}{{H}_{5}}){{P}^{+}}\bar{\ddot{C}}HC{{H}_{2}}C{{H}_{3}}\] to form phosphoniumylide, which then gives alkenes. The formed alkenes then reacts with \[{{B}_{2}}{{H}_{6}}\] to give addition product, alkane which is in accordance to antimarkownikofFs rule.