Isolation, structural assignment and insecticidal activity of (−)-(1S,2R,3R,4S)-1,2-epoxy-1-methyl-4-(1-methylethyl)-cyclohex-3-yl acetate, a natural product from Minthostachys tomentosa
Hydrolytic Enantioselective Protonation of Cyclic Dienyl Esters and a β-Diketone with Chiral Phase-Transfer Catalysts
摘要:
Hydrolytic enantioselective protonation of dienyl esters and a beta-diketone catalyzed by phase-transfer catalysts are described. The latter reaction is the first example of an enantio-convergent retro-Claisen condensation. Corresponding various optically active alpha,beta-unsaturated ketones having tertiary chiral centers adjacent to carbonyl groups were obtained in good to excellent yields and enantiomeric ratios (83-99%, up to 97.5:2.5 er).
work reports a metal-free method for deuteriumlabeling covering a broad range of substrate including phenolic compounds (i.e. flavonoids and stilbenes), indoles, pyrroles, carbonyl compounds, and steroids. This method was also applied for commonly used drugs such as loxoprofen, haloperidol, stanolone, progesterone, androstenedione, donepezil, ketorolac, adrenosterone, cortisone, pregnenolone, and dexamethasone
在这里,我们揭示了一种简单的卤化氘 (DX) 生成方法,该方法由合成化学实验室中现成的普通且廉价的试剂制成,i . e . 在温和条件下,异戊二烯基、烯丙基和炔丙基卤化物。我们设想,原位生成酸卤化氘可用于酸催化反应,并可用于有机催化氘化。本工作报告了一种无金属氘标记方法,覆盖范围广泛的底物,包括酚类化合物(即. 类黄酮和芪)、吲哚、吡咯、羰基化合物和类固醇。该方法也适用于常用药物,如洛索洛芬、氟哌啶醇、甾烷酮、黄体酮、雄烯二酮、多奈哌齐、酮咯酸、肾上腺素、可的松、孕烯醇酮和地塞米松。这项工作证明了一些氘代化合物的克级无色谱合成。这项工作提供了一种简单、清洁且无副产物的位点选择性氘代,并且氘代产物无需色谱分离即可获得。当将这些引发剂用于其他酸催化反应时,DX 的氘同位素效应可能会提供不同于使用普通酸的反应所获得的产物。虽然异戊二烯卤化物自发转化为酸的机制尚不清楚,
A (π2 + π2) photocycloaddition reaction as a facile route to angularly substituted cis-hydrindanes and cis-decalanes
作者:M. Van Audenhove、D. De Keukeleire、M. Vandewalle
DOI:10.1016/s0040-4039(00)93662-1
日期:1980.1
The photochemical addition of 1,2-bis(trimethylsiloxy) cyclobutene to, respectively, 2-cyclopentenones and 2-cyclohexenones represents a novel and facile entry into angularly substituted bicyclo[4.3.0]nona-2,5-diones and bicyclo-[4.4.0]deca-2,5-diones.
Allyl-Nickel Catalysis Enables Carbonyl Dehydrogenation and Oxidative Cycloalkenylation of Ketones
作者:David Huang、Suzanne M. Szewczyk、Pengpeng Zhang、Timothy R. Newhouse
DOI:10.1021/jacs.9b02552
日期:2019.4.10
of carbonyl compounds using allyl-nickel catalysis. This development overcomes several limitations of previously reported allyl-palladium-catalyzed oxidation, and is further leveraged for the development of an oxidative cycloalkenylation reaction that provides access to bicycloalkenones with fused, bridged, and spirocyclic ring systems using unactivated ketone and alkene precursors.
METHYL MENTHOL DERIVATIVE AND COOLING AGENT COMPOSITION CONTAINING SAME
申请人:TAKASAGO INTERNATIONAL CORPORATION
公开号:US20180057447A1
公开(公告)日:2018-03-01
The purpose of the present invention is to provide a cooling agent composition containing a novel methyl menthol derivative having no undesirable feeling of stimulation, malodor, bitterness, or the like, it being possible to use the cooling agent composition as a cooling agent or sensory stimulation agent having exceptional persistence of a sense of coolness and refreshing feeling. The present invention pertains to a cooling agent composition containing a methyl menthol derivative represented by general formula (1A) or general formula (1B).
Der stereochemische verlauf der alkalischen epoxydation von α,β-ungesättigten carbonylverbindungen der cyclischen monoterpenreihe
作者:E. Klein、G. Ohloff
DOI:10.1016/s0040-4020(01)99364-0
日期:1963.1
In the cyclic monoterpenes, the base-catalysed epoxidation1 of endocyclic double bonds which are in conjugation with carbonyl groups follows a highly stereoselective course resulting in a single epimer. Exocyclic double bonds are attacked from both sides in this reaction.