1: With 2,2'-bis(picolinoyloxy)-(1S)-1,1'-binaphthalene; silver hexafluoroantimonate; copper dichloride in dichloromethane T=-78°C; 3 h; 2: With titanium tetrachloride in dichloromethane T=0°C; 0.5 h; 3: With hydrogenchloride in methanol T=60°C; 12 h; Title compound not separated from byproducts;

1: CrO3, aq. H2SO4 / acetone 2: aq. HCl View Scheme

hydrogenchloride; titanium(III) chloride; TADDOL multistep reaction; enantioselective conjugative addition of silylketeneacetals to 2-carbalkoxycyclopentenones promoted by TADDOL*TiCl2 complexes.;