The compound of molecular formula `C _(5) H _(10)O (A)` reacts with Tollen's reagent to give silver mirror but does not undergo aldol condensation. The compound A is

Options

A. a) 3-pentanone
B. b) 2,2-dimethylpropanal
C. c) 3-hydroxy-2-pentene
D. d) 3-methylbutanal

Answer

B

Explanation

Since the compound reacts with Tollen.s reagent so it must contain a- CHO (aldehyde) group. Further, it does not give aldol condesation it means that in it , `alpha -` hydrogen atom (s) is (are ) absent. The structure of the given compound is as
`{:(CH _(3) overset(alpha ) ( CH_(2))overset(O) overset(||) ( C) - overset(alpha ) ( CH_(2)) CH _(3)), (" ""3-pentanone"), (" ""NO-CHO group but"), (" "alpha - H"atoms present"):}{:(overset(alpha ) (CH _(3))overset( CH _(3) ) overset( |) underset( CH _(3)) underset(|) (C) - CHO), (" " "2,2 dimethyl propanaol"), (("have -CHO group and no" alpha -H "atom is present ")):}`
`underset( ("NO- CHO group"))underset( "3- hydroxt -2- pentene")( CH _(3) - CH = overset( OH) overset(|) (C)- CH _(2) CH _(3)) underset(("have - CHO group and " alpha - H "atom"))underset("3-methyl butanal") ( CH _(3) overset(CH _(3) ) overset(|) (C) overset(alpha ) ( CH _(2)) CHO )`
`underset(("No - GHO group and one" alpha -H "atom"))(CH _(3) overset( CH _(3)) overset(|) (CH) - overset(O) overset(||) (C) - CH _(3))`
Thus A is 2,2-dimenthylpropanal (as it contains a - CHO group but no `alpha-H` atom).