How would you do the following conversions in not more than two steps?
(i) Propanone to Propene
(ii) Propanal to Butaonone
(iii) Ethanol to 3-Hydroxybutanol
(iv) Benzaldehyde to Benzophenone
(v) Benzaldehyde to `alpha`-Hydroxyphenylacetic acid
(vi) Benzaldehyde to 3-Phenylpropan -1-ol

Explanation

(a)`CH_(3)COCH_(3) overset(LiAlH_(4))to CH_(3)overset(OH)overset(|)(CH)-CH_(3) overset(H^(+), 453 K) to CH_(3)CH-= CH_(2)`
(b) `CH_(3)CH_(2)CHO overset(CH_(3)MgBr) underset(H_(3)O^(+)) to CH_(3)-CH_(2) -overset(OH)overset(|)(CH)-CH_(3) overset(K_(2)Cr_(2)O_(7)//H^(+)) to CH_(3)CH_(2)-overset(O)overset(|)C-CH_(3)`
(c) `CH_(3)CH_(2)OH overset(O) to underset(2"moles") to CH_(3)CHO overset(OH^(-))underset("Aldol condensation") to CH_(3)-overset(OH)overset(|)(CH)-CH_(2)CHO`
(d)