The nature of the reaction
between α-alkyl-γ-(p-nitrophenyl)allyl
chlorides (1)-(3), which have the general form p-O2NC6H4CH=CHCH(Cl)R, and a
variety of nucleophiles depends on the alkyl group R and the nucleophile. The
chloride (1) (R = Me) undergoes ionic (SN2
and subsequent Michael addition) processes with the salt (7) of 2-nitropropane
to give products (15) and (16) whereas the chloride (2) (R = Pr1)
gives a mixture of products (17) and (18) which are shown to arise by a
radical-chain nucleophilic substitution process, with allylic rearrangement-an SRNl' reaction-and ionic processes respectively.
The chloride (3) (R = But) gives the SRN1' product (25)
with the salt (7). Other nucleophiles with (2) and (3) appear to react by ionic
(SN2 and SN2') and/or SRNl' processes; e.g. (3) gives an excellent
yield of the malononitrile (32) by an SN2'
process when treated with the sodium salt (9).
