Organocatalysis by Hydrogen Bonding Networks
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Scheme 4. Dynamic kinetic resolution of azlactones 6 by alcoholytic ringopening, effected by the bifunctional organocatalysts 8
Oxazinones of the general structure 7 are configurationally stable.
Consequently, alcoholytic ring opening with a chiral organocatalyst was
expected to afford kinetic resolution (KR), but no DKR (Scheme 6). In
fact, a number of oxazinones could be resolved kinetically and with excellent selectivity (Scheme 7; Berkessel et al. 2005). Figure 6 shows
a typical time course for the kinetic resolution of a β
3 -amino acid derived oxazinone.