Die katalytische Hydrierung der enolisierbaren ?-Keto-?-lactone
作者:F. Fleck、A. Rossi、M. Hinder、H. Schinz
DOI:10.1002/hlca.19500330121
日期:——
Bei derHydrierungder in β-oder γ-Stellung alkylierten, enolisierbaren α-Keto-γ-lactone bzw. ihrer Enolacetate in Gegenwart von Palladium-Calciumcarbonat oder Raney-Nickel entstehen quantitativ die entsprechenden α-Oxy-γ-lactone bzw. ihre Acetate. In neutralem, saurem und alkalischem Milieu wird immer nur das eine derbeiden möglichen Diastereomeren erhalten.
Biocatalytic Synthesis of Homochiral 2-Hydroxy-4-butyrolactone Derivatives by Tandem Aldol Addition and Carbonyl Reduction
作者:Carlos J. Moreno、Karel Hernández、Samantha Gittings、Michael Bolte、Jesús Joglar、Jordi Bujons、Teodor Parella、Pere Clapés
DOI:10.1021/acscatal.3c00367
日期:2023.4.21
hydroxymethyltransferase (KPHMTEcoli), 2-keto-3-deoxy-l-rhamnonate aldolase (YfaUEcoli), and trans-o-hydroxybenzylidene pyruvate hydratase-aldolase from Pseudomonas putida (HBPAPputida) and (ii) subsequent 2-oxogroup reduction of the aldol adduct by ketopantoate reductase from E. coli (KPREcoli) and a Δ1-piperidine-2-carboxylate/Δ1-pyrroline-2-carboxylate reductase from Pseudomonas syringae pv. tomato DSM 50315
Wittig Rearrangements of Boron-Based Oxazolidinone Enolates
作者:Zirong Zhang、David B. Collum
DOI:10.1021/acs.joc.9b01426
日期:2019.9.6
[2,3]-Sigmatropic rearrangements (Wittig rearrangements) of α-alkoxy oxazolidinone enolates are described. Whereas alkali metal enolates fail, owing to facile deacylation, boron enolates generated from di-n-butylboron triflate and triethylamine rearranged in good yields and high selectivities with exceptions noted. IR and NMR spectroscopies show the boron is chelated by the α-alkoxy group rather than