cheminform abstract: pd-catalyzed reactions of donor—acceptor-substituted cyclopropanes and their...

2001 indan derivatives

indan derivativesQ 1050

07 - 090Pd-Catalyzed Reactions of Donor–Acceptor-Substituted Cyclo-propanes and Their Ring-Opened Derivatives: Attempted HeckCyclization and Novel One-Pot Enolate Arylations. — Alkylationof siloxycyclopropanecarboxylates (I), generated by cyclopropanation reactionof the corresponding silyl enol ethers with diazoacetate, with iodophenylmethyliodide (II) provides the title donor–acceptor-substituted cyclopropane deriva-tives (III). Attempts to synthesize indan derivatives (IV) by Et3N–HF-mediatedcyclopropane ring opening followed by intramolecular Heck reaction are notvery successful. In contrast, in the presence of fluoride ions intramoleculararylation of the cyclopropane derivatives (III) is achieved in one-pot proce-dure to give target indan derivatives (IV) in moderate yields. Interestingly,cyclization of acetal-protected enone (VIII) provides access to a novel tricyclicsystem (IX). — (KHAN, FAIZ AHMED; CZERWONKA, REGINA; REISSIG,HANS-ULRICH; Eur. J. Org. Chem. (2000) 21, 3607-3617; Inst. Org. Chem.,TU Dresden, D-01062 Dresden, Germany; EN)

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