Allene epoxidation: synthesis of functionalized lactones by the DMDO oxidation of allenic acids
作者:Jack K Crandall、Elisa Rambo
DOI:10.1016/s0040-4020(02)00698-1
日期:2002.8
products are formed directly from allene oxides, keto lactones are formed. The corresponding spirodioxide intermediates give lactones with appropriately situated α-hydroxyketone moieties. An understanding of the regiochemistry of the epoxidations and the subsequent cyclizations of the reactiveintermediates is developed, as are methods for the manipulation of the experimental conditions to favor the
Ru-Catalyzed Isomerization of Achmatowicz Derivatives: A Sustainable Route to Biorenewables and Bioactive Lactones
作者:Miroslav Dangalov、Adolfo Fernández-Figueiras、Martin A. Ravutsov、Ekaterina Vakarelska、Maya K. Marinova、Nuno R. Candeias、Svilen P. Simeonov
DOI:10.1021/acscatal.2c04867
日期:2023.2.3
A Ru-catalyzed isomerization of Achmatowicz derivatives that opens unexplored routes to diversify the biogenic furanic platform is reported. The mechanistic insights of this formally redox-neutral intramolecular process were studied computationally and by deuterium labeling. The transformation proved to be a robust synthetic tool to achieve the synthesis of bioderived-monomers and a series of 4-keto-δ-valerolactones
报道了 Achmatowicz 衍生物的 Ru 催化异构化,该异构化开辟了使生物源呋喃平台多样化的未开发途径。通过计算和氘标记研究了这种正式的氧化还原中性分子内过程的机理见解。该转化被证明是一种强大的合成工具,可实现生物衍生单体和一系列 4-酮基-δ-戊内酯的合成,进一步促进了合成乙酰基合成的灵活策略的发展。还描述了两种天然产物(即 ( S , S )-muricatacin 和 ( S , S )-L-因子)的简洁且无保护基团的不对称全合成。
Rationalizing the Origin of Solerone (5-Oxo-4-hexanolide): Biomimetic Synthesis and Identification of Key Metabolites in Sherry Wine
作者:Dietmar Häring、Peter Schreier、Markus Herderich
DOI:10.1021/jf960316j
日期:1997.2.1
A biomimetic synthesis of solerone (5-oxo-4-hexanolide, 1) using both enzymatic and acid-catalyzed reactions was performed. Starting from L-glutamic acid 5-ethyl ester (2) enzymatic oxidative deamination followed by subsequent decarboxylation of the corresponding 2-oxoglutaric acid Ei-ethyl ester (3) led to ethyl 4-oxobutanoate (4). In the presence of pyruvate, 4 served as key substrate for a novel acyloin condensation catalyzed by pyruvate decarboxylase (EC 4.1.1.1) from Saccharomyces cerevisiae. Finally, the resulting ethyl 4-hydroxy-5-oxo-hexanoate (5) was easily converted into solerone (1) in the presence of acid. The acyloin condensation of 3 with acetaldehyde to ethyl 5-hydroxy-4-oxohexanoate (6) revealed an alternative route to solerone (1). Acid-catalyzed lactonization of 6 produced 4-oxo-5-hexanolide (7) as well as 5 and 1 via keto-enol tautomerization. Confirming the relevance of the proposed biogenetic pathway, the solerone precursors 2-6 as well as delta-lactone 7 were identified in sherry by GC/MS analysis for the first time.