Stereochemical Study of a Lewis Acid-Promoted Reaction of 2-Silyloxypyrrole with Aliphatic and Aromatic Aldehydes

Article abstract of DOI:10.1246/bcsj.72.1533

In the presence of BF3*OEt2, the reaction of 1-t-butoxycarbonyl-2-t-butyldimethylsiloxypyrrole with aliphatic and aromatic aldehydes in ether occurred stereoselectively to give the corresponding erythro and threo isomers, respectively, while a similar reaction in the presence of SnCl4 showed completely opposite selectivity. The transition states leading to the major isomers are discussed.