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

Substrate
(60)
(61)
(62)
(63)
R = OAc R= OH
Time (min)
30 30
150 1440
30 30
30 30
47
Product
Chapter Two
R = OAc R= OH
Yield (%)
96 91
94 a -
95 93
92 b 94 b
Table 2.5 Reactions of allylic acetates and alcohols with acetyl chloride and ethanol
a 6.7:1 mixture of (E)-1-chloro-2-nonene and 3-chloro-1-nonene
b 1:1 mixtures of isomeric chlorides
Roy and co-worker’s, building on previous work conducted by De Luca et al. [30] in the
synthesis of alkyl chlorides using cyanuric chloride (TCT), achieved the synthesis of
unsymmetrical allylic chlorides using TCT with DMF (Scheme 2.17). [45, 46] The results
showed that the product formed was dependent on the electronic and steric nature of the
substituents (Table 2.6). In entries 1 and 3, chlorine addition occurs on the less hindered
site, whereas in entry 4 complete tele-substitution occurs. However, in entry 2, elimination
occurs affording the conjugated diene, whilst in entry 5 the presence of an electron
withdrawing group, means that formation of the ipso-substituted product is favoured in
contrast to the tele-substituted product.
Scheme 2.17 Reaction of allylic alcohols with TCT and DMF
(For a definition of R see Table 2.6)