Lewis acids 1,5 anhydro 2,3,4 tri o acetyl dextro threo pent 1 enitol 2 1,5 anhydro 2,3,4 tri s phenyl 2,3,4 trithio dextro,levo threo pent 1 enitol 2 2 benzylthio 2h pyran 3(6h) one 2 2 phenylthio 2h pyran pyran 3(6h) one 2 Alkenes 2 Catalysis 2 Dihydropyranone 2 Epoxidation 2 Glycosylations 2 Hypervalent Iodine 2 Iodine 2 Lewis acid 2 Pentoses 2 Phenols 2 Polysubstitution 2 Pyrans 2 Reduction 2 Rhodium 2 Stereoisomerism 2 Substitution reactions 2 Sugar (sucrose) 2 Sulfhydryl Compounds 2 Synthesis (chemical) 2 Thiols 2 acetonitrile 2 alcohol derivative 2 article 2 carbonyl derivative 2 catalysis 2