Biomedical Engineering Reference
In-Depth Information
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SCHEME 2.16
Ugi metathesis methodology.
Lee et al. have demonstrated that the products of the Ugi-Diels-Alder process are
excellent staring points for the preparation of products that rival the complexity of
natural products. Intermediates from the process developed by Paulvannan (i.e., when
the acid is fumaric acid monobenzylamide) can be double-allylated with base and allyl
bromide (Scheme 2.16). Treatment of
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with Grubbs's metathesis catalyst results
in a ring-closing/ring-opening/ring-closing metathesis cascade that forms two new
seven-membered rings [47]. In a subsequent example, exquisite control of metathesis
regiochemistry could be exerted, based on the diastereomeric configuration of the
