Question

(B) Complete each synthesis by giving missing starting material, reagent, or products:
\includegraphics[width=0.5\linewidth]{ch32i.png}

Hint:

\textbf{Quick Tips for Organic Synthesis:} \begin{itemize} \item \textbf{(a)} Aldehydes react with hydroxylamine (\(\ce{HO-NH2}\)) in the presence of an acid to form oximes, which are useful intermediates in organic synthesis. \item \textbf{(b)} Ozonolysis cleaves double bonds in alkenes, producing carbonyl compounds (aldehydes or ketones) depending on the structure of the starting alkene. \item \textbf{(c)} Thionyl chloride (\(\ce{SOCl2}\)) is a common reagent for converting alcohols to alkyl chlorides, with gaseous byproducts (\(\ce{SO2}\) and \(\ce{HCl}\)) that are easy to remove. \end{itemize}

Answer 1

(a) \[ \ce{O} + \ce{HO-NH2} \xrightarrow{\ce{H+}} \ce{NH2OH} \] The reaction involves the formation of hydroxylamine (\(\ce{NH2OH}\)) from an aldehyde (\(\ce{O}\)) and hydroxylamine (\(\ce{HO-NH2}\)) in the presence of an acid catalyst (\(\ce{H+}\)). (b) \[ \ce{CH2=CH2} \xrightarrow{\text{(i) } O_3 \text{ (ii) } Zn-H_2O} \ce{2HCHO} \xrightarrow{\Delta} \text{No further change} \] The reaction involves ozonolysis of ethene (\(\ce{CH2=CH2}\)) followed by reductive workup to form formaldehyde (\(\ce{HCHO}\)). Heating (\(\Delta\)) does not change the product further. (c) \[ \ce{OH} \xrightarrow{\ce{SOCl2}} \ce{Cl} \] The reaction involves the conversion of an alcohol (\(\ce{OH}\)) to an alkyl chloride (\(\ce{Cl}\)) using thionyl chloride (\(\ce{SOCl2}\)) under heating (\(\Delta\)). (d) \[ \ce{CHO} \xrightarrow{\ce{NaCN/HCl}} \ce{COOH} \] The reaction involves the conversion of an aldehyde (\(\ce{CHO}\)) to a carboxylic acid (\(\ce{COOH}\)) using sodium cyanide (\(\ce{NaCN}\)) and hydrochloric acid (\(\ce{HCl}\)). (e) \[ \ce{Cl2C6H5} \xrightarrow{\ce{CH3}} \ce{Cl2C6H4CH3} \] The reaction involves the methylation of chlorobenzene (\(\ce{Cl2C6H5}\)) to form a methylated chlorobenzene derivative (\(\ce{Cl2C6H4CH3}\)).