Complete the following and point out the mechanism as `SN^2,SN^1,E1,E2`, or none.
(a) `Me_2C=CHC1 + NaN NH_2`
(b) `CH_3CH_2Br + ddot Pme_3`
(c) `BrCH_2CH_2CH_2Br + I^(Ө)`
(d) `BrCH_2(CH_2)_2CH_2Br + Mg` (ether)
( e) `Me_3 CBr + HCOOH + HCOO^(Ө)` (small amount)
(f) `Me_3 CBr + HCOOH`
(g) `CH_3 CH_2 CH_2 Br + LiA1D_4`.

Explanation

(a) No reaction (`overset (overset(Ө)ddot) N H_2` is a strong base but cannot remove vinylic `C1`).
(b) `CH_3 CH_2 -overset (oplus)P Me_3 (SN^2)`
(intramolecular `SN^2`) + some `[I(CH_2)_3I]` is formed by typical `SN^2`.
(d) `BrMgCH_2(CH_2)_2CH_2MgBr` [It is difficult to form four-membered ring by an intramolecular `SN^2` by the first formed carbanion
`(MgBr)^(oplus) overset (Ө) CH_2(CH_2)CH_2Br` displaceing `Br^(Ө)`].
(e) `{:(Me_(3)C-O-overset(overset(O)(||))(C)-H(SN^(1))+Me_(2)C=CH_(2)("Minor")),((E1)),((HCOO^(Theta)) "is a weak base and its concentration is low)"):}`
(f) `Me_(3)C-O-overset(overset(O)(||))(C)-H(SN^(1))`
(g) `CH_(3)CH_(2)CH_(2)D. (SN^(2)) [{:("LiAID"_(4)", a source"),("of" D^(Ӫ)", as LiAIH"_(4) "is"),("a source of H"^(Ӫ)):}]`.