1: With dirhodium(II) tetrakis[methyl 4(R)-2-oxazolidinone-4-carboxylate] in dichloromethane 2 h; Heating; 2: With trifluoroacetic acid T=20°C; 5 h; Title compound not separated from byproducts;

1: With dirhodium(II) tetrakis[methyl 4(R)-2-oxazolidinone-4-carboxylate] in dichloromethane 2 h; Heating; 2: With trifluoroacetic acid T=20°C; 5 h; Title compound not separated from byproducts;