D A Evans. D. Barnes Carbonyl Ylids: Dipolar Cycloaddition (and More! )-3 Chem 206 Application of Carbonyl Ylids to the Synthesis of Zaragozic acid TBS Rh(I) HO-C /+Buo,C-o C=o Ylid Transforms t-BuO,C -OTBs 58 HO C TMSO If you are anxious for over-exposure, Rh2 (oAc)4 Sir John Cornforth to good food and good drink, without leisure to think erck,719949185 Zaragozic Acid skeleton A= CO,H HOC HOC Hodgson et al. J. Chem. Soc. Perkin Trans 1, 2000, 3432 灬0 CHO-CO2R HOC ROCD. A. Evans, D. Barnes Carbonyl Ylids: Dipolar Cycloaddition (and More!)–3 Chem 206 O R O MeO2C N2 TMSO O R O MeO2C TMSO O R O MeO2C Merck, TL 1994 9185 TMSO (66%) Zaragozic Acid Skeleton H O O O OH HO2C HO2C OH CO2H Ph OAc Me Ph O Me Application of Carbonyl Ylids to the Synthesis of Zaragozic acid: H RO O O R OH HO2C HO2C OH CO2H H RO O O R OH HO2C HO2C OH CO2H C=O Ylid Transforms H RO O O R OH HO2C HO2C OH CO2H H RO OH OH R OH HO2C HO2C OH CO2H O O HO2C O R OH H OR H OH A HO2C H A = CO2H O HO2C O R OH H OR H OH A HO2C H Hodgson et al. J. Chem. Soc. Perkin Trans I, 2000, 3432 RO2C O O R OR OR RO2C N2 O OR OR R O CHO–CO2R EtO2C N2 O OTBS OTBS Me O Rh(II) RO2C O O R OTBS OTBS O t-BuO2C H O EtO2C O R OTBS H OTBS H O t-BuO2C H 58% yield Rh2 (OAc)4 If you are anxious for over-exposure, to prepublication disclosure, to good food and good drink, without leisure to think, try IUPAC symposia." Sir John Cornforth: