How will you convert ethnal into the following compounds ?
i. Butane-1,3-idol , ii. But-2-enal
iii. But-2-enoic acid

Explanation

`( i) 2CH_3 CHO underset( "aldol condensation ") overset(OH^(-)) to CH_3 overset(OH) overset(|) CH - underset("Aldol")(CH_2)- underset(O ) overset(||)C-H overset(LiAIH_4) to underset("Butane -1,3-diol") (CH_3 overset(OH) overset(| ) CH-CH_2CH_2OH)`
(ii ) `2CH_3 CHO CHO underset("Aldol condensation") overset(OH^-) to CH_3 overset(OH) overset(|)CH -CH_2CHO underset("Heat")overset(H^+) to CH_3 underset("Butane -2-enal ") (CH_4 CH=CH-CHO)`
`(iii ) 2CH_3 CHO underset("aldol condensation ") overset(OH^(-)) to CH_3 overset(OH) overset(|) CH CH_2 CHO underset("heat")overset(H^(+) .H_2 O) to CH_3 CH= CH-CHO overset( LiAIH_4 , H^+) to {:(CH_3 CH=CHCH_2 OH ),( darr KMO_4 ","H^+),(CH_3 CH =CHCOOH),("but -2- enoic acid "):}`