Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

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Chapter Two
chloroenamine at room temperature in DCM. Primary alcohols were converted in excellent
yields (95-99 %), whilst the secondary allylic alcohol evaluated afforded the desired product
in slightly lower yield (84 %), since there was also formation of the rearranged chloride
(Scheme 2.16).
Scheme 2.16 Chlorination of But-3-en-2-ol
More recently Yadav and Babu [44] have reported a simple, inexpensive and high yielding
procedure for the conversion of allylic acetates and alcohols into the corresponding
chlorides using acetyl chloride and ethanol. The process consists of mixing 1 equivalent of
allylic acetate/alcohol with 8 equivalents of ethanol and acetyl chloride and stirring at 23 ºC,
until the reaction is complete by TLC, after which the solvent is removed in vacuo to afford
the chlorinated product. Selected results are summarised in Table 2.5. All of the reactions
conducted with allylic acetate were very high yielding and selective, with the exception of
substrates (61) and (63), where mixtures were obtained. The allylic alcohols were for the
most part as reactive and selective as the corresponding allyl acetate, however, substrate
(61) reacted very slowly, after 24 hours only traces of the allylic chlorides were formed,
with additional equivalents of AcCl and EtOH failing to improve the product yield.