Figure 1. Chemical structures of the lactones 1, 2 and 3.

Scheme 1.

Figure 2. GC Chromatograms of racemic (solid line) lactones and their coinjections with authentic enriched (dashed line) lactones. Inserts: GC chromatograms of the recovered lactones (R)-1 (e.e. >97%), (R)-2 (e.e. >95%), and (R)-3 (e.e. >70%) at 50% conversion.

Figure 3. Plots of reaction temperature versus lactone conversion in Novozym-435-catalyzed resolution of lactones 1 (), 2 (▪) and 3 (●) at 23, 40 and 60°C after 5 h. No reaction was observed at 0°C even after 24 h.

Figure 4. Plots of reaction temperature versus % e.e. of recovered (R)-lactone in Novozym-435-catalyzed resolution of lactones 1 (), 2 (▪) and 3 (●) at 23, 40 and 60°C after 46% (±1%) lactone conversion. No reaction was observed at 0°C even after 24 h.

Figure 5. A cartoon representation of the lipase active site and its binding to the lactone.

Table 1. Novozym-435 catalyzed solvent-free kinetic resolution of 1, 2, and 3 with n-butanola