D. H. Ripin, D. A. Evans The Eschenmoser Coupling Reaction-2 Chem 206 Reagents for the Reaction MHCO MOH MH. MOR Organic: R3N, N-methylmorpholine, buffered solutions Thiophiles: Ar3P, R3P, (RO)3P - BuO2C H Rapoport. Org. Chem. 46, 3230(1981) IMe2 PhP 此Em8m6:gn A Eschenmoser Science 196, 1410(1977) NaH Meo CH2)2CO2Me Eto2C a)1.05 eqiv(PhcoO) Me T Kametani J. Chem. Soc, Perkin Trans. 11607 (1980) 84%0 ( CH2)22 Me CO2t-Bu △RaN,68% R2 Me S Danishefsky R2 Tet Lett. 30. 362 (CH2)2CO2Me (CH2)2CO2Me R364% carbenes Thioethers s-Ylids H23-08-Eschenmoser-2 11/5/008: 27 PMcarbenes Thioethers S-Ylids : + – + Rh(OAc)2 ∆ Ra-Ni, 68% + ii NaOH S. Danishefsky Tet. Lett. 30, 3625 (1989) 99% * 79% DBU NaH CuBr T. Kametani J. Chem. Soc., Perkin Trans. I 1607 (1980) mix Et3N, PPh3 H. Rapoport J. Org. Chem. 46, 3230 (1981) 64% t-BuOK t-BuOH, 25 °C P(CH2CH2CN)3, TFA, sulfolane A. Eschenmoser Science 196, 1410 (1977) This center readily epimerizes to a 2:1 mix of diaster. in favor of the shown. b) P(OEt)3, Xylene, ∆ a) 1.05 eqiv. (PhCOO)2 84% (+) H. Rapoport J. Org. Chem. 46, 3230 (1981) A. Eschenmoser Helv. Chim. Acta. 54, 710 (1971) Bases: Inorganic: MHCO3, MOH, MH, MOR Organic: R3N, N-methylmorpholine, buffered solutions Thiophiles: Ar3P, R3P, (RO)3P Combination: 2 2 D. H. Ripin, D. A. Evans The Eschenmoser Coupling Reaction-2 Chem 206 Reagents for the Reaction: PhP NMe2 PhP N O N Bn t-BuO2C S TfO Me CO2Bn O O t-BuO2C N Bn Me O O CO2Bn N H MeN OAc S Br CO2Me Ar CO2Et MeN CO2Et OAc N H CO2MeBr OMe Me N MeO Me CO2Me OAc NMe EtO2C N2 HN O S CO2t-Bu N CO2t-Bu O CO2t-Bu N S O N2 S N –O CO2t-Bu O CO2t-Bu N S S R S R N H N O O Me Me (CH2)2CO2Me O Me (CH2)2CO2Me Me Me O S N H O (CH2)2CO2Me Me Me O N Me H (CH2)2CO2Me (CH2)2CO2Me Me Me S N R Me O N O H N H N O O Me Me R3 Me Me R3 Me R2 Me R3 O R2 Me R2 N NH NH N MeO2CCH2 Me MeO2CCH2 O (CH2)2CO2Me Me MeO2CCH2 Me Br R R R C R R R H23-08-Eschenmoser-2 11/5/00 8:27 PM