C O M M U N I C A T I O N S
Scheme 3
in optical purity and was converted to amurensinine ((+)-1) as a
single enantiomer.
In summary, we have developed a convergent and enantiose-
lective synthesis of amurensinine that takes advantage of sequential
C-H and C-C bond insertion reactions to build the core structure
of the isopavines in a rapid fashion. A palladium-catalyzed enantio-
selective aerobic oxidation of hydroxysilane (()-17 was utilized
to generate enantioenriched amurensinine ((+)-1). Our work under-
scores the utility of selective C-H and C-C bond insertion reac-
tions for strategic planning of multistep syntheses and provides the
first demonstration of the oxidative kinetic resolution in the context
of natural product synthesis. Development and applications of these
powerful reactions are ongoing.
Scheme 4 a
Acknowledgment. The authors are grateful to the NIH-NIGMS
(R01 GM65961-01), NDSEG (predoctoral fellowships to U.K.T.
and D.C.E.), NSF (predoctoral fellowship to D.C.E.), A. P. Sloan
Foundation, Research Corporation, Bristol-Myers Squibb, Amgen,
Merck, Pfizer, Novartis, Lilly, Roche, Abbott, AstraZeneca, and
Caltech for financial support.
Supporting Information Available: Experimental details. This
References
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Scheme 5
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of >47. Conversion of the enantioenriched alcohol (-)-17 to azide
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than 99% ee. Azide (-)-18 was then transformed to the desired
secondary lactam (+)-16 in three simple steps. Importantly, the
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