A novel chemoenzymatic synthetic cascade enables the preparation of densely decorated tetrahydrofuran building blocks. Here, the lipase-catalyzed desymmetrization of 3-alkoxyglutarates renders highly enantioenriched carboxylic acid intermediates, whose subsequent activation and oxonium ylide rearrangement by means of rhodium or copper complexes furnishes functionalized O-heterocycles with excellent diastereoselectivity. The two-step protocol offers a streamlined and flexible synthesis of tetrahydrofuranones bearing different benzylic, allylic or allenylic side chains with full control over multiple stereogenic centers.
Keywords: chemoenzymatic; heterocycles; lipase; sigmatropic; transition metal catalysis.
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