Organic & Biomolecular Chemistry
Paper
ability of the system to stabilise the intermediate carbocation mined through comparing the integration due to a signal
as demonstrated by the relative rates of the two processes corresponding to the starting material relative to the inte-
(
shown in Scheme 2 and summarised in Tables 1 and 2), it is gration of a signal due to the product ether (see ESI†). This
has a very minor effect upon the extent to which the electronic allowed calculation of observed first order rate constants for
nature of the substituents affects reaction outcome.
the methanolysis of the alcohols under these conditions. The
kinetic analysis for each alcohol was carried out in triplicate.
Conclusions
Acknowledgements
The above results demonstrate that whilst introducing anti-
aromatic character into a carbocation intermediate may SRDG acknowledges the support of the Australian government
dramatically affect the rate of reaction, it does not necessarily through the receipt of an Australian Postgraduate Award.
change the mechanism of reaction where a viable alternative JBH acknowledges financial support from the Australian
pathway is not available. Further, it demonstrates that the Research Council Discovery Project Funding Scheme (Project
transmission of electronic effects in antiaromatic systems are DP130102331). The authors would like to acknowledge the
comparable to those in aromatic systems. This has impli- NMR Facility within the Mark Wainwright Analytical Centre at
cations for the reactivity of larger polycyclic hydrocarbons with the University of New South Wales for NMR support.
antiaromatic character.
Notes and references
Experimental
1
2
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1
13
(
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Full synthetic procedures can be found in the ESI† as per
the reaction schemes shown throughout the Results and Dis-
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alcohols 3b–3i had not been previously prepared so were fully
characterised, whilst the remainder had physical and spectral
data matching that reported in literature (see ESI† for full
details).
The corresponding methyl ethers (6a–c and 6e–h and 8a–e)
were isolated after being treated with acidic methanol at reflux
for 3 hours (full details of the preparation, along with appro-
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8
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