Abstract
Novel bicyclo[n.2.0]alkan-1-ols with incorporation of methyl substitution at the C6
bridgehead and C2 position on a six-member ring, and incorporation of methyl substitution
at the C2 position on a five-member ring were obtained. The presence or absence of
a group at these positions had a role in the preference of the major stereochemical
isomer observed. Potential limitations of the cyclisation methodology was observed
when the ketone was hindered (camphor), and where conjugation was present in the enolate.
By contrast, another functional group, as illustrated with 1,4-cyclohexanedione mono-ethylene
ketal 24, can be incorporated in the bicyclo[4.2.0]octan-1-ol, and the ketal group converted
to a ketone, as in 28 , without disrupting the bicyclo[4.2.0]octan-1-ol ring.
Key words
bicyclic compounds - cyclisations - ketones - sulfoxides - sulfones
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