(a) Why does `3^@ RX` rarely undergo `E1` reaction ?
(b) How can `E1` be promoted ?
(c) Give the products in the following reaction.

(d) Give the products of `MeONa` with
(i) cis and
(ii) trans-2-Bromomethy1 cyclohexane.

Explanation

(a) `3^@` reacts by `E1` only when the base is weak, or
(i) Has a very low concentration.
(ii) As the base gets stronger or more concentrated `E2` prevails
(iii) If base is too weak or too dilute, `R^+` reacts with the nucleophilic solvent to give `SN^1` product.
(iv) In non-polar solvent, `RX` does not react.
(b) By using electrophilic catalysis, `e.g.,` with `Ag^(oplus)` or `Pb^(2 +)` aids in ionisation of `(C-X)` bond.
(c) (A) `CH_3CH = CH_2 (EtO^(Ө)` is a strong base , `E2` takes place with `2^@ RX` over `SN^2`).
(B) `CH_3CH(OEt)CH_3 (EtOH` is a weaker base but stronger nucleophile, so `SN^1` is favoured.)
(i)
(ii) .