Give the alkene formed on heating the following (Hofmann degradation) :
i. `[overset(beta)(CH_(3))overset(alpha)(CH_(2))-overset(Me)overset(|)underset(Me)underset(|)(N)-overset(alpha)CH_(2)-overset(beta)(CH_(2))-CH_(3)]^(o+)overset(Theta)OH`
ii.
iii. `
iv.
v.` .

Explanation

i. Less-substituted alkene ` CH_3 = CH_2` is formed , not ` CH_2 = CH- CH_3`
i.
iii. Here, Saytzeff product is formed not Hofman product because enxylic (H) atom's acidic character is greatly increased and the stability of the conjugated alkene influences the reaction .
`PH -CH = CH_2` is formed , Not `CH_2 =CH_2.`
iv. It gives

and `CH_(2)=CH_(2) +t-Bu NMe_(2) (7%)`
The result is Saytzeff product, not Hofmann product. There are two kinds of `1^(@) beta-H` atoms, one on `CH_(3)CH_(2)` and other on any `CH_(3)` of the `3^(@) Bu` group. Thus in this case, relative acidities are not a factor. Elimination from the `t-Bu` group is favoured statistically (there are nine of these `C(CH_(3))_(3)`, vs three from `CH_(3)CH_(2))` and also because a more stable alkene is formed.
v. `PH-CH=CH_(2)` is formed, not [same explanation as in (ii) above]