A Straightforward Homologation of Carbon Dioxide with Magnesium Carbenoids en Route to α-Halocarboxylic Acids
作者:Serena Monticelli、Ernst Urban、Thierry Langer、Wolfgang Holzer、Vittorio Pace
DOI:10.1002/adsc.201801614
日期:2019.3.5
homologation of carbon dioxide with stable, (enantiopure) magnesium carbenoids constitutes a valuable method for preparing α‐halo acid derivatives. The tactic features a high level of chemocontrol, thus enabling the synthesis of variously functionalized analogues. The flexibility to generate magnesium carbenoids through sulfoxide‐, halogen‐ or proton‐ Mg exchange accounts for the wide scope of the reaction.
Pheromones 80.<sup>1</sup>Synthesis of (<i>S</i>)-(+)-Manicone and (<i>S</i>)-(+)-Normanicone, Mandibular Gland Constituents of Myrmicine Ants
作者:Valerij Martischonok、Gagik G. Melikyan、Alfred Mineif、Otto Vostrowsky、Hans Jürgen Bestmann
DOI:10.1055/s-1991-26515
日期:——
Optically active (4E,6S)-(+)-4,6-dimethyloct-4-en-3-one (10a), manicone, and (3E,5S)-(+)-3,5-dimethylhept-3-en-2-one (10b), normanicone, the biologically active stereoisomers of mandibular gland alarm pheromone components of Manica ants, were synthesized by three different routes starting from (S)-(-)-2-methylbutan-1-ol (1).
Aldehyde to Ketone Homologation Enabled by Improved Access to Thioalkyl Phosphonium Salts
作者:Meghan Fragis、Jackson L. Deobald、Srinivas Dharavath、Jeffrey Scott、Jakob Magolan
DOI:10.1021/acs.orglett.1c01189
日期:2021.6.18
to competing redox chemistry with sulfoxides. Here we circumvent this problem to achieve a formal phosphine Pummerer reaction that offers thioalkyl phosphonium salts that, in turn, give rise to diverse vinyl sulfides via Wittig olefinations. Thirty vinyl sulfides are thus prepared from (alkylthioalkyl)triphenyl phosphonium salts and aldehydes. The hydrolysis of these vinyl sulfides offers an efficient
The alkylation of enone with 1-chloroalkyl phenyl sulfoxide followed by treatment with thiophenolate afforded α-phenylthio-β, γ-unsaturated carbonylcompound, which was oxidized and then hydrolyzed to give α, β-unsaturated γ-hydroxy carbonylcompound in good yield.
α-phenylthio β,γ-unsaturated carbonyl compound through an α,β-epoxy sulfoxide. Oxidation of the sulfide with 2.1 equivalents of m-chloroperbenzoic acid gave α,β-unsaturated γ-phenylsulfinyloxy carbonyl compound via sulfoxide-sulfenate rearrangement. The sulfinate was easily hydrolyzed with aqueous potassium hydroxide to afford α,β-unsaturatedγ-hydroxy carbonyl compound in good yield. When optically active