Sc(OTf)3-catalyzed smooth tandem [3+2] cycloaddition/ring opening of donor–acceptor cyclopropane 1,1-diesters with enol silyl ethers
作者:Jie Fang、Jun Ren、Zhongwen Wang
DOI:10.1016/j.tetlet.2008.09.028
日期:2008.11
Catalyzed by Lewis acids, donor-acceptor cyclopropane 1,1-diesters reacted with enol silyl ethers to afford 1,6-dicarbonyl compounds in moderate to excellent yields. This supplied a mild carbon-carbon bond-forming method from the ring opening of cyclopropanes. A smooth tandem [3+2] cycloaddition/ring opening process has been clearly proved by an independent experiment. (C) 2008 Elsevier Ltd. All rights reserved.
Ring Opening of Donor–Acceptor Cyclopropanes with Acyclic 1,3-Diketones for the Synthesis of 1,6-Dicarbonyl Compounds
α-position of acetophenone derivatives to donor–acceptorcyclopropanes, were synthesized in two steps via first ringopening of donor–acceptorcyclopropanes with acyclic 1,3-diketones followed by DBU catalyzed retro-Claisen-type C–C bond cleavage reactions. In the first step, acyclic 1,3-diketones selectively worked as C-nucleophiles to add to donor–acceptorcyclopropanes. In the second step, the alkyl ketone