ORGN 868 |
| The oxidative cyclisation of a range of substrates to give cis-THFs is described. A number of initiator groups have been investigated for reactivity in this osmium (VI) catalysed process. In particular, 1,3-diols and hydroxy-amides cyclise in excellent yields to give cis-substituted THFs via a concerted [3+2] cycloaddition of an osmium glycolate ester to give the heterocyclic product. The reaction is stereoselective with respect to formation of 2,5-syn products and stereospecific with respect to addition across the alkene moiety. Enantiopure starting materials have also been demonstrated to cyclise without loss of optical purity.
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Heterocycles and Aromatics
8:00 AM-12:00 PM, Thursday, 14 September 2006 Moscone Center -- Room 135, Oral
Division of Organic Chemistry |
