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DOI: 10.1055/sos-SD-203-00270

Jautze, S.; Peters, R.Science of Synthesis: Stereoselective Synthesis, (20113464.

A catalytic, asymmetric, domino Claisen rearrangement/intramolecular carbonyl-ene reaction based on previous studies on the catalytic, asymmetric Claisen rearrangement (see Section and on copper-catalyzed ene reactions[‌52‌] has been reported (Scheme 17).[‌53‌] The bis(4,5-dihydrooxazole) catalyst 2 promotes the formation of two new CC bonds in almost quantitative yield and three stereocenters (two of which are quaternary) with excellent enantioselectivity and high catalyst-induced diastereocontrol. The reaction sequence proceeds via formation of an intermediate α-oxo ester 62 from enone precursor (E)-61. This intermediate is suitable for bidentate coordination to the chiral copper catalyst 2, thereby inducing an intramolecular carbonyl-ene reaction. The formation of two diastereomers 63A and 63B is a consequence of incomplete enantioselection in the Claisen rearrangement. Utilizing the isomeric substrate (Z)-61 with a Z-configured O-allyl moiety reverses the diastereomeric ratio.

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