55802-98-7Relevant articles and documents
Terpene Cyclizations inside a Supramolecular Catalyst: Leaving-Group-Controlled Product Selectivity and Mechanistic Studies
Zhang, Qi,Catti, Lorenzo,Pleiss, Jürgen,Tiefenbacher, Konrad
supporting information, p. 11482 - 11492 (2017/08/30)
The tail-to-head terpene cyclization is arguably one of the most complex reactions found in nature. The hydrogen-bond-based resorcinarene capsule represents the first man-made enzyme-like catalyst that is capable of catalyzing this reaction. Based on noncovalent interactions between the capsule and the substrate, the product selectivity can be tuned by using different leaving groups. A detailed mechanistic investigation was performed to elucidate the reaction mechanism. For the cyclization of geranyl acetate, it was found that the cleavage of the leaving group is the rate-determining step. Furthermore, the studies revealed that trace amounts of acid are required as cocatalyst. A series of control experiments demonstrate that a synergistic interplay between the supramolecular capsule and the acid traces is required for catalytic activity.
Synthesis of a comprehensive polyprenol library for the evaluation of bacterial enzyme lipid substrate specificity
Wu, Baolin,Woodward, Robert,Wen, Liuqing,Wang, Xuan,Zhao, Guohui,Wang, Peng George
, p. 8162 - 8173 (2014/01/06)
Polyprenols, a universal class of glycan-carrier lipids, play important roles in glycan biosynthesis in wide variety of living organisms. The chemical synthesis of natural polyisoprenols such as undecaprenol and dolichols, and even more so the synthesis o
Staphylococcus aureus penicillin-binding protein 2 can use depsi-lipid ii derived from vancomycin-resistant strains for cell wall synthesis
Nakamura, Jun,Yamashiro, Hidenori,Miya, Hiroto,Nishiguchi, Kenzo,Maki, Hideki,Arimoto, Hirokazu
supporting information, p. 12104 - 12112 (2013/09/23)
Vancomycin-resistant Staphylococcus aureus (S. aureus) (VRSA) uses depsipeptide-containing modified cell-wall precursors for the biosynthesis of peptidoglycan. Transglycosylase is responsible for the polymerization of the peptidoglycan, and the penicillin-binding protein 2 (PBP2) plays a major role in the polymerization among several transglycosylases of wild-type S. aureus. However, it is unclear whether VRSA processes the depsipeptide-containing peptidoglycan precursor by using PBP2. Here, we describe the total synthesis of depsi-lipid I, a cell-wall precursor of VRSA. By using this chemistry, we prepared a depsi-lipid II analogue as substrate for a cell-free transglycosylation system. The reconstituted system revealed that the PBP2 of S. aureus is able to process a depsi-lipid II intermediate as efficiently as its normal substrate. Moreover, the system was successfully used to demonstrate the difference in the mode of action of the two antibiotics moenomycin and vancomycin. Copyright
Reductive deprotection of allyl, benzyl and sulfonyl substituted alcohols, amines and amides using a naphthalene-catalysed lithiation
Alonso, Emma,Ramon, Diego J.,Yus, Miguel
, p. 14355 - 14368 (2007/10/03)
The reaction of different protected alcohols, amines and amides with lithium and a catalytic amount of naphthalene (4 mol %) in THF at low temperature leads to their deprotection under very mild reaction conditions, the process being in many cases chemoselective.
SYNTHESIS OF THE SAN JOSE SCALE'S SEX PHEROMONE COMPONENT USING AN AVAILABLE NATURALLY OCCURRING STARTING MATERIAL
Novak, Lajos,Poppe, Laszlo,Kis-Tamas, Attila,Szantay, Csaba
, p. 17 - 24 (2007/10/02)
(Z)-3,7-Dimethyl-2,7-octadien-1-yl propanoate (1), a component of the San Jose scale (Quadraspidiotus perniciosus, Comstock) pheromone, was prepared by the multistage isomerisation of the C6 carbon-carbon double bond of the readily available compound, nerol (3).The synthesis was carried out via the epoxide by subsequent LiAlH4 ring cleavage and Hofmann-like mesylate elimination.
STEREOSELECTIVE SYNTHESIS OF A CISOID C10 ISOPRENOID BUILDING BLOCK AND SOME ALL-CIS-POLYPRENOLS
Sato, Kikumasa,Miyamoto, Osamu,Inoue, Seiichi,Furusawa, Fumio,Matsuhashi, Yasusuke
, p. 725 - 728 (2007/10/02)
As the key compound for the construction of cisoid terpenoids, (2Z,6Z)-8-benzyloxy-1-chloro-2,6-dimethylocta-2,6-diene was sinthesized stereoselectively via the Wittig reaction starting from nerol.The ten-carbon building block was coupled with prenyl or neryl p-tolyl sulfone to afford, after reductive desulfonylation, (Z,Z)-farnesol and (Z,Z,Z)-nerylnerol, respectively.
Stereoselective Synthesis of Moenocinol and Assignment of Its Carbon-13 Nuclear Magnetic Resonance Spectrum
Coates, Robert M.,Johnson, Mark W.
, p. 2685 - 2697 (2007/10/02)
A stereoselective synthesis of moenocinol (1), the sesquiterpene alcohol liberated by hydrolysis of the antibiotic moenomycin, is described.Alkylation of isobutyric acid dianion with 5-bromo-1-pentene followed by reduction with lithium aluminum hydride and benzylation provided 1-benzyloxy-2,2-dimethyl-6-heptene (4).Hydrolysis and cleavage of the epoxide of 4 with periodic acid gave 6-benzyloxy-5,5-dimethylhexanal (6). 2-Phenylthio-6-benzyloxy-5,5-dimethylhexanoic acid (8a) was prepared from 6 by chromic acid oxidation and α-phenylsulfenylation.Reaction of the dianion of 8a with geranyl bromide followed by esterification and hydride red uction afforded phenylthio alcohol 10a.Simultaneous reductive elimination and debenzylation of the corresponding acetate (10b) with lithium in ammonia gave (E)-2,2,8,12-tetramethyl-5-methylene-7,11-tridecadien-1-ol (11). (Z)-1-Benzyloxy-6-bromo-3-methyl-4-hexene (17b) was prepared from the benzyl ether of nerol by the following four steps: regioselective ozonolysis, borohydride reduction, formation of the tosylate and displacement with bromide ion.The reaction of the Grignard reagent from 17b with the aldehyde (12) secured by oxidation of 11 afforded an alcohol which was oxidized to (2Z,13E)-1-benzyloxy-3,8,8,14,18-pentamethyl-11-methylene-2,13,17-nonadecatrien-7-one (33).The 6,7-trans (Z) enol phosphate 34, formed by phosphorylation of the enolate anion of 33, underwent reduction with lithium in ammonia to (2Z,6E,13E)-3,8,8,14,18-pentamethyl-11-methylene-2,6,13,17-nonadecatetraen-1-ol (1) which was identical with moenocinol obtained from moenomycin.The 6,7-cis isomer (32b) of moenocinol was also prepared by a Wittig reaction between aldehyde 12 and phosphorane 18 and subsequent reductive debenzylation.Carbon-13 NMR spectral data for synthetic and natural moenocinol compared favorably; a consistent set of assignments for the 13C NMR absorptions is deduced from comparisons with model compounds.
