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A Route to Carbasugar Analogues - Jonathan Clayden - The ...

A Route to Carbasugar Analogues - Jonathan Clayden - The ...

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Chapter 4 – Synthesis of carbasugars<br />

of cyclic homoallylic alcohols such as 344 is unlikely <strong>to</strong> occur since it would form syn<br />

6,6 bicycle 345.<br />

Other interesting cycli<strong>to</strong>ls might be made by using different organolithium<br />

nucleophiles <strong>to</strong> introduce more interesting functional groups. Cyclohexyllithium<br />

would be expected <strong>to</strong> work similarly <strong>to</strong> isopropyllithium, allowing the synthesis of<br />

disaccharide mimics such as 346. Use of THP-Li 215 would allow access <strong>to</strong> more<br />

oxygenated analogues such as 347, whilst silicon nucleophiles could be oxidised <strong>to</strong><br />

give compounds such as 348 which resembles the inosi<strong>to</strong>l family. Fluorinated dienes<br />

102d and 102e have been synthesised in modest yield; these could offer an alternative<br />

method of synthesising alkyl fluorides from a range of commercially available aryl<br />

fluorides.<br />

HO<br />

HO<br />

HO<br />

HO<br />

HO<br />

O<br />

HO<br />

OH<br />

HO<br />

OH<br />

HO<br />

OH<br />

HO<br />

OH<br />

OH<br />

OH<br />

OH<br />

Nu = c-Hex<br />

346<br />

Nu = THP<br />

347<br />

Nu = SiMe 2 Ph<br />

348<br />

Ox*<br />

Ox*<br />

102d<br />

F<br />

F<br />

102e<br />

Scheme 4.62 – possible synthetic targets and starting materials<br />

183

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