How will you convert ethanal into the following compounds ?
(i) Butane -1, 3 - diol
(ii) But -2- enal
(iii) But -2- enoic acid.

Explanation

(i) `underset("Ethanal")(2CH_(3)CHO)overset("Dil. NaOH")underset("(Aldol condensation)")rarr underset("3 - Hydroxybutanal")(overset(4)CH_(3)-overset(3)CHOH-overset(2)CH_(2)-overset(1)CHO)overset(NaBH_(4))underset("(Reduction)")rarrunderset("Butane -1, 3 - diol")(overset(4)CH_(3)-overset(3)CHOH-overset(2)CH_(2)overset(1)CH_(2)OH)`
(ii) `underset("Ethanal")(2CH_(3)CHO)overset("Dil. NaOH")underset("(Aldol condensation)")rarrunderset("3 - Hydroxybutanal")(overset(4)CH_(3)overset(3)-CHOHoverset(2)-CH_(3)overset(1)-CHO)overset(Delta)underset(-H_(2)O)rarrunderset("But - 2- enal")(CH=CH-CHO)`
(iii) `underset("Ethanal")(CH_(3)CHO)overset("Dil. NaOH")underset(Delta,-H_(2)O)rarrunderset("But - 2- enal")(CH_(3)CH=CHCHO)overset([Ag(NH_(3))_(2)]^(+)OH^(-))underset("Tollens. reagent")rarrunderset("But - 2- enoic acid")(CH_(3)CH=CHCO_(2)H)`