17393-17-8Relevant articles and documents
One-pot synthesis of cyclopropane derivatives with a cis : Trans stereoselectivity by Wittig olefination-sulfur ylide cyclopropanation sequence
Huang, Wenhua,Wang, Lai-Ling
, p. 380 - 384 (2013/07/26)
Cyclopropane derivatives were synthesised in one pot from aromatic aldehydes, phenacyltriphenylphosphonium bromide, and S-phenacylthiolanium bromide by a Wittig olefination-sulfur ylide cyclopropanation sequence. When Cs2CO3 was used as the base and CH3CN/water (8:2, v/v) as the solvent, the major product was the cis-1,2-dibenzoyl cyclopropane. In contrast, when using DBU as the base and MeOH as the solvent, the major product was transdibenzoyl cyclopropane. In some cases, the major isomer was obtained in high purity and good yield by simple filtration.
The direct preparation of functionalised cyclopropanes from allylic alcohols or α-hydroxyketones using tandem oxidation processes
McAllister, Graeme D.,Oswald, Magalie F.,Paxton, Richard J.,Raw, Steven A.,Taylor, Richard J.K.
, p. 6681 - 6694 (2007/10/03)
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.
Tandem oxidation processes for the preparation of functionalized cyclopropanes
Oswald, Magalie F.,Raw, Steven A.,Taylor, Richard J. K.
, p. 3997 - 4000 (2007/10/03)
(Chemical Equation Presented) A novel manganese dioxide-mediated tandem oxidation process (TOP) has been developed which allows the direct conversion of allylic alcohols into cyclopropanes, the intermediate aldehydes being trapped in situ with a stabilized sulfur-ylide. This methodology has been applied successfully to a variety of allylic alcohols and to a formal synthesis of the simple, naturally occurring lignan, (±)-picropodophyllone.
