Consider the given reaction:
\(\rm CH_3 CHO \xrightarrow[(ii) \ NaBH_4]{(i) \ dil \ NaOH}\)
1
\(\rm H_3C - CH_2 - CH_2 - COOH\)
2
\(\begin{array}{*{20}{c}} {\rm {H_3}C - C - C{H_2} - C{H_2} - COOH}\\ {|| \ \ \ \ \ \ \ \ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\ {\rm O \ \ \ \ \ \ \ \ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \end{array}\)
3
\(\begin{array}{*{20}{c}} \rm{{H_3}C - CH - C{H_2} - C{H_2} - OH}\\ {| \ \ \ \ \ \ \ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\ {\,\,\,\,\,\,\rm OH \ \ \ \ \ \ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \end{array}\)
4
\(\rm H_3C - CH_2 - CH_2 - CHO\)