McAllister, G.D., Oswald, M.F., Paxton, P.J., Raw, S.A. and Taylor, R.J.K. (2006) The direct preparation of functionalised cyclopropanes from allylic alcohols or a-hydroxyketones using tandem oxidation processes. Tetrahedron, 62 (12). pp. 6681-6694. ISSN 0040-4020
New manganese dioxide-mediated tandem oxidation processes (TOPs) have been developed, which facilitate the direct conversion of allylic alcohols and α-hydroxyketones into polysubstituted functionalised cyclopropanes. In the simplest version, the oxidation of an allylic alcohol is carried out in the presence of a stabilised sulfurane, and the intermediate α,β-unsaturated carbonyl compound undergoes in situ cyclopropanation. By using a combination of stabilised phosphorane and sulfurane, the direct conversion of allylic alcohols or α-hydroxyketones into functionalised cyclopropanes is achieved, with in situ cyclopropanation being followed by Wittig olefination, or vice versa. The application of these methods to a formal synthesis of the lignan (±)-picropodophyllone, and to novel analogues of the insecticide allethrin II, is described.
|Institution:||The University of York|
|Academic Units:||The University of York > Chemistry (York)|
|Depositing User:||York RAE Import|
|Date Deposited:||04 Mar 2009 16:55|
|Last Modified:||04 Mar 2009 16:55|
|Publisher:||Elsevier Science B.V., Amsterdam.|