Seok-Hwi Park

Stereoselective Chirality Extension of syn,anti- and syn,syn-Oxazine and Stereochemical Analysis of Chiral 1,3-Oxazines: Stereoselective Total Syntheses of (+)-1-Deoxygalactonojirimycin and (−)-1-Deoxygulonojirimycin

This paper describes the stereoselective total syntheses of (+)-1-deoxygalactonojirimycin and (-)-1-deoxygulonojirimycin via new chiral building blocks syn,anti,syn-oxazine 11a and syn,syn,anti-oxazine 13a. These were accomplished in four steps in 44.1 and 33.7% overall yields, respectively. These chirons were derived from the stereoselective addition of a nucleophile to the corresponding aldehydes of syn,anti-oxazine 10 and syn,syn-oxazine 12. Furthermore, this paper describes the stereochemical analysis of three types of chiral 1,3-oxazines; anti,syn-, syn,anti-, and syn,syn-oxazines using the NOESY technique.

Formal Synthesis of (+)-α-Conhydrine and Stereoselective Synthesis of Pyrrolidine Analogue via the Diastereoselective Chelation-Controlled Hydride Reduction and Wittig Reaction

Abstract Asymmetric syntheses of (+)-α-conhydrine and its pyrrolidine analogue were achieved from readily available L-serine. The key step involved highly diastereoselective chelation-controlled hydride reduction of the amino ketone to give the anti-amino alcohol and Wittig reaction. GRAPHICAL ABSTRACT