Tetrahedron

Synthesis of 3, 6-dihydro-2H-pyran-2-ones via cationic palladium (II) complex-catalyzed tandem [2+ 2] cycloaddition-allylic rearrangement of ketene with α, β- …

T Hattori, Y Suzuki, Y Ito, D Hotta, S Miyano

Index: Hattori, Tetsutaro; Suzuki, Yutaka; Ito, Yuuichi; Hotta, Daido; Miyano, Sotaro Tetrahedron, 2002 , vol. 58, # 26 p. 5215 - 5223

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Citation Number: 22

Abstract

Treatment of ketene with α, β-unsaturated aldehydes and ketones in the presence of [Pd (dppb)(PhCN) 2](BF4) 2 leads to the formation of 4-vinyloxetan-2-ones, which rearrange under the conditions to give 3, 6-dihydro-2H-pyran-2-ones in a variety of yields, depending on the substituents. Asymmetric induction with up to 57% de has been achieved by using α, β-unsaturated aldehydes bearing an asymmetric carbon center at the β-position. A ...