Palladium-Catalyzed Asymmetric Synthesis of 2-Alkynyl Oxacycles
作者:David S. B. Daniels、Amber L. Thompson、Edward A. Anderson
DOI:10.1002/anie.201105720
日期:2011.11.25
cyclizations of cyclic and acyclic propargylic carbonates give 2‐alkynyl oxacycles. The reactions proceed with very high stereoselectivity for both syn‐ and anti‐disubstituted furans and pyrans, and with exceptional regioselectivity. In addition, two‐directional cyclizations of bis‐propargylic carbonate substrates yield bifurans with complete stereocontrol for all diastereomers.
A Convenient and Chemoselective One-Pot Oxidation/Wittig Reaction for the C<sub>2</sub>-Homologation of Carbohydrate-Derived Glycols
作者:Fernando R. Pinacho Crisóstomo、Romen Carrillo、Tomás Martín、Fernando García-Tellado、Víctor S. Martín
DOI:10.1021/jo051566e
日期:2005.11.1
A simple and convenientone-pot protocol for the chemoselectiveC2-homologation of carbohydrate-derivedglycols is described. The method comprises the chemoselectiveoxidation of the glycol to the corresponding hydroxyaldehyde and the subsequent Wittig alkenylation. In addition, the method does not need selective protective group manipulation, and it is safe, economical, fast (5 to 6 h), and bench-friendly
Montmorillonite K-10 as a mild acid for the Nicholas reaction
作者:Fernando R. Pinacho Crisóstomo、Romen Carrillo、Tomás Martín、Víctor S. Martín
DOI:10.1016/j.tetlet.2005.02.118
日期:2005.4
The use of Montmorillonite K-10 as a convenient acid component in the Nicholas reaction is described. Its use permits functional selectivity, inter- and intramolecular reactions and convenience in the experimental conditions. A four-step one-pot [CO2(CO)(6)-acetylene complex formation, THP-removal, cyclization and complex cleavage] process permits the direct synthesis of 2-ethynyl-tetrahydrofuraii from 6-(tetrahydro-2H-pyran-2-yloxy)hex-1-yn-3-ol. (c) 2005 Elsevier Ltd. All rights reserved.
Enantioselective synthesis of (S)-γ-acetylenic γ-aminobutyric acid (GABA)
作者:Andrew B. Holmes、Alethea B. Tabor、Raymond Baker
DOI:10.1039/p19910003301
日期:——
The enantioselectivesynthesis of (S)-γ-acetylenicγ-aminobutyricacid (GABA)1 by phthalimide displacement of the (R)-prop-2-ynylic alcohol 12(generated from acetal 4) is reported.