P. Sibi and James W. Christensen

Department of Chemistry, North Dakota State University, Fargo ND, 58105-5516, Sibi -plains. nodak. edu 

Two separate solutions of Red Star active dry yeast (or other supermarket variety, 20 g) and sodium alginate (5g) each in water (200 mL) were prepared by very slow addition of the respective reagent to the rapidly stirred solvent. 

When each solution became an homogeneous viscous fluid, they were combined and added dropwise via an addition funnel to calcium chloride (670 mL of 10% (w/v)). The droplets formed gelatinous beads upon impact with the salt solution. The size and shape of the beads may be adjusted by the rate of addition. 

The beads were washed five times with water (portions of 500 mL), and used immediately in the reduction of ketone. 

2 BAKERS YEAST REDUCTION OF (Z)-N-CARBOBENZYLOXY-3-KETOPROLINE ETHYL ESTER 

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