68492-45-5Relevant academic research and scientific papers
Regioselective 1,4-Conjugate Addition of Grignard Reagents to α,β-γ,δ-Dienones and α,β-γ,δ-Dienyl Thiol Esters
Amoah, Emmanuel,Dieter, R. Karl
, p. 2870 - 2888 (2017)
Alkyl Grignard reagents (Et, nBu, iPr, cyclohexyl), with the exception of tBuMgCl, undergo exclusive or exceptionally highly regioselective 1,4-addition reactions to α,β-γ,δ-unsaturated ketones, while aryl and heteroaryl Grignard reagents give mixed results ranging from exclusive 1,4-addition (1-naphthyl, 2-N-methylpyrrolyl) to regioselective 1,2-addition (2-furyl, 2:1). All alkyl, aryl, and heteroaryl Grignard reagents examined gave exclusive 1,4-addition reactions with α,β-γ,δ-unsaturated thiol esters, with the exception of tBuMgCl, which gave an 80:20 mixture of 1,4:1,6-addition products. The high chemo- and regioselectivity observed for these reactions is attributed to a radical or radical-like pathway for the alkyl Grignard reagents and possibly a carbanion pathway for aryl Grignard reagents. The α,γ-dienyl thiol esters provide for a one-pot tandem 1,4-addition-nucleophilic acyl substitution reaction sequence to afford 3-substituted 4-enone moieties.
The Reactions of Acetals with Silyl Enol Ethers Promoted by the Combination of Tin(II) Chloride and Organic Halide. Novel and Convenient Synthesis of α,β-Unsaturated Ketones
Oriyama, Takeshi,Iwanami, Katsuyuki,Miyauchi,Yuka,Koga, Gen
, p. 3716 - 3718 (2007/10/02)
Acetals react with silyl enol ethers to give condensation products in good yield by the action of a reactive halide such as acetyl chloride or methoxymethyl chloride along with a catalytic amount of SnCl2.The procedure employing excessive amount of halide offers a novel and convenient method to synthesize conjugated enones.
