Highly Stereoselective Synthesis of trans-l,2-Cyclopropane Derivatives from Semistabilized Arsonium Ylides by Phase-Transfer-Catalysis Reactions

摘要

Semistabilized arsonium ylides, generated in situ from the corresponding arsonium salts in the biphasic system of dichlo-romethane-50% aqueous sodium hydroxide, reacted smoothly with electron-deficient alkenes to afford trans-1,2-cyclopropane derivatives with high stereoselectivity. The synthesis of trans-l,2-cyclo-propane derivatives in the presence of sodium hexamethyl-disilazanide (1.0 M solution in THF) were also studied.A variety of arsonium ylides have been investigated in organic synthesis.1 These ylides have also been used in the stereoselective synthesis of cyclopropane derivatives, which can easily be converted into other diverse and useful building blocks.The cyclopropane ring is frequently found in the skeletons of many natural products and substances of biological and pharmaceutical interest.3 We have previously reported that the stabilized arsonium ylide, derived from an arsonium salt in the presence of potassium carbonate, reacts with electron-deficient alkenes to give czs-l,2-cyclopropane derivatives with high stereoselectivity in good yields.