1: With bromine in dichloromethane T=-78 - 20°C; 1 h; 2: With pyridine in dichloromethane T=20°C; 0.5 h;

triphenylphosphine hydrobromide; dimethyl sulfoxide T=80 - 85°C; 6 h; Inert atmosphere;

1,8-diazabicyclo[5.4.0]undec-7-ene; 1,3-bis(2,4,6-trimethylphenyl)imidazolinium chloride in tetrahydrofuran T=20°C; Inert atmosphere; optical yield given as percent destereoselective reaction;