Among the following the number of compounds which will give positive iodoform reaction is ______.
(a) 1-Phenylbutan-2-one
(b) 2-Methylbutan-2-ol
(c) 3-Methylbutan-2-ol
(d) 1-Phenylethanol
(e) 3, 3-dimethylbutan-2-one
(f) 1-Phenylpropan-2-ol

The iodoform test is positive for compounds containing either a $$CH_3CO-$$ group (methyl ketone) or a $$CH_3CH(OH)-$$ group (secondary alcohol with methyl group adjacent to OH).

Analyzing each compound:

(a) 1-Phenylbutan-2-one (C₆H₅CH₂COCH₂CH₃): The carbonyl has CH₂ groups on both sides, not a methyl group. Negative ✗

(b) 2-Methylbutan-2-ol ((CH₃)₂C(OH)CH₂CH₃): This is a tertiary alcohol with no CH₃CHOH pattern. Negative ✗

(c) 3-Methylbutan-2-ol (CH₃CH(OH)CH(CH₃)₂): Has a CH₃CHOH group. Positive ✓

(d) 1-Phenylethanol (C₆H₅CH(OH)CH₃): Has a CH₃CHOH group. Positive ✓

(e) 3,3-Dimethylbutan-2-one (CH₃COC(CH₃)₃): Has a CH₃CO group. Positive ✓

(f) 1-Phenylpropan-2-ol (C₆H₅CH₂CH(OH)CH₃): Has a CH₃CHOH group. Positive ✓

Number of compounds giving positive iodoform test = 4 (c, d, e, f).