THE HIGH STEREOSELECTIVE SYNTHESIS OF β-ALKYNYL-ENOL PHOSPHATES
摘要:
A high stereoselective synthesis for beta -allcynyl-enol phosphates from beta -alkynyl ketone and dialkyl phosphite, via Atherton-Todd reaction, was reported. NaH as base gave a nearly pure Z-isomer.
Synthesis of homopropargyl alcohols via sonochemical Barbier-type reaction
作者:Adam Shih-Yuan Lee、Shu-Fang Chu、Yu-Ting Chang、Shu-Huei Wang
DOI:10.1016/j.tetlet.2003.12.058
日期:2004.2
were synthesized from the reaction mixture of zinc powder, 1,2-diiodoethane, 3-bromo-1-propyne and aldehyde or ketone in anhydrous THF under ultrasound. The homopropargyl alcohols were obtained as the only product in all cases when aldehydes were reacted with 3-bromo-1-propyne under this sonochemical Barbier-type reaction condition. The homopropargyl alcohol was produced as the major product and the
Highly Selective Synthesis of Acetylenic Alcohols Promoted by Metallic Dysprosium in the Presence of Mercuric Chloride
作者:Zhiming Li、Yu Jia、Jingyao Zhou
DOI:10.1080/00397910008087415
日期:2000.7
Abstract Promoted by metallic dysprosium, carbonyl compounds react smoothly with propargyl bromide to afford the corresponding homopropargylic alcohols in good to excellent yields without observation of allenic alcohols. In addition, this reaction is regioselective and chemoselective.
The firstexample of lead-promoted “Barbier-type” (in situ Grignard) reaction has been demonstrated by the reaction of propargyl bromide with aldehydes in a Pb/Bu4NBr/Me3SiCl/DMF system.
Electrophilic Cyclization and Intermolecular Acetalation of 2-(4-Hydroxybut-1-yn-1-yl)benzaldehydes: Synthesis of Diiodinated Diepoxydibenzo[<i>c</i>,<i>k</i>][1,9]dioxacyclohexadecines
strategy for the preparation of diiodinated diepoxydibenzo[c,k][1,9]dioxacyclohexadecines from readily available 2-(4-hydroxybut-1-yn-1-yl)benzaldehydes through electrophile-triggered tandem cyclization/intermolecular acetalation sequence has been presented. The electrophilic macrocyclization can be performed under mild conditions and in up to gram quantities. Moreover, palladium-catalyzed coupling and
Isomerizations on silica gel: Synthesis of allenyl ketones and the first Nazarov cyclizations of vinyl allenyl ketones
作者:A Stephen、K Hashmi、Jan W Bats、Ji-Hyun Choi、Lothar Schwarz
DOI:10.1016/s0040-4039(98)01619-0
日期:1998.10
chromatographic workup of crude, terminal propargyl ketones 5 on silica gel directly leads to terminal allenylketones 6. When the other substituent on 5 was electron-rich, 7 was observed as side-product. If the other substituent on 5 was electron-poor, the isomeric 1-propynyl ketone 8 was the side-product. Chromatography of the crude propargyl vinyl ketones 10 on silica gel delivers the products of a Nazarov