How would the ratio of products change if.
(i) `R = Et`
(ii)
(iii) .

Explanation

(i)
(ii)
The steric effect causes a decrease in `1,2-addition` product. Hence, as `R` changes from `Et rarr i-Pr rarr t-Bu, 1,4-addition` increases in this order.
`IUPAC` names of the compounds :
`A rArr` Hex-2-en-2-one
`B rArr` Ethyl magnesium bromide
`C rArr` 3-Ethylhex-4-en-3-ol
`D rArr` 5-Methylheptan-3-one
`E rArr` 2-Methyl hex-4-en-3-one
`F rArr` 3-Ethyl-2-methylhex-4-en-3-one
`G rArr` 2,5-Dimethyl hepan-3-one
`H rArr` 2,2-Dimethyl hex-4-en-3-one
`I rArr` 3-Ethyl-2,2-dimethyl hex-4-en-3-ol
`J rArr` 2,2,5-Trimethyl heptan-3-one.