Total synthesis of (−)-centrolobine: β-C-glycoside formation via a tandem Grignard addition and stereoselective hemi-ketal reduction

It has been demonstrated that an aryl-β-C-glycoside can be efficiently constructed via a sequence consisting of Brown asymmetric allylation, ring-closing metathesis, hydrogenation, nucleophilic addition, and stereoselective Et3SiH reduction. The antibiotic natural product (−)-centrolobine was synthesized in this manner utilizing only five steps with an overall 53% yield.