Author/Authors :
Sarkar، نويسنده , , Shaheen M. and Taira، نويسنده , , Yuko and Nakano، نويسنده , , Ayako and Takahashi، نويسنده , , Keisuske and Ishihara، نويسنده , , Jun and Hatakeyama، نويسنده , , Susumi، نويسنده ,
Abstract :
Quinine and quinidine were synthesized by a highly enantio- and stereoselective approach starting from a proline-catalyzed asymmetric cycloaldolization of benzyl bis(2-formylethyl)carbamate which gave a 70:30 mixture of (3R,4R)-N-Cbz-3-hydroxymethyl-4-hydroxypiperidine (96% ee) and its 4S-epimer (92% ee) in 94% yield after in situ NaBH4 reduction.
Keywords :
organocatalyst , total synthesis , Cycloaldolization , Cinchona alkaloids , asymmetric synthesis
