Reagents Mechanism Intermediate Regiochemistry
Stereochemistry
Hydrogenation H2/Pd/C Concerted None No Syn
Bromination Br2 Ionic Bromonium
ion No Anti
Halohydrin Formation Br2/H2O Ionic Bromonium
ion Yes Anti
Hydrohalogenation HBr Ionic Carbocation Yes No
Hydration H2O/H2SO4 Ionic Carbocation Yes No
Dihydroxylation 1.
OsO4 Concerted None No Syn
2.
NaHSO3