Highly Regio-and Stereoselective Cocyclotrimerization and Linear Cotrimerization of α, β-Unsaturated Carbonyl Compounds with Alkynes Catalyzed by Nickel …

T Sambaiah, LP Li, DJ Huang, CH Lin…

Index: Sambaiah; Li; Huang; Lin; Rayabarapu; Cheng Journal of Organic Chemistry, 1999 , vol. 64, # 10 p. 3663 - 3670

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Citation Number: 64

Abstract

Cyclic enones 2-cyclohexen-1-one (1a), 4, 4-dimethyl-2-cyclohexen-1-one (1b), 2- cyclopenten-1-one (1c), and 2-cyclohepten-1-one (1d) react with octa-1, 7-diyne (2) in THF in the presence of Ni (PPh3) 2I2, ZnI2, and Zn powder at 62° C to give [2+ 2+ 2] cycloaddition-dehydrogenation products 3a-d in 32-80% yields. α, β-Unsaturated lactone 5a (5, 6-dihydro-2 H-pyran-2-one) undergoes [2+ 2+ 2] cycloaddition with 2 to give both the ...