15848-22-3Relevant articles and documents
Pheromones: 87. An efficient synthesis of (6E,11Z)-6,11-hexadecadienyl acetate and (6E,11Z)-6,11-hexadecadienal: Female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera: Saturniidae)
Bestmann,Gunawardena
, p. 1239 - 1241 (1992)
(6E,11Z)-Hexadecadienyl acetate (15) and the corresponding aldehyde 16, the female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera; Saturniidae) have been synthesized in 32% and 27% overall yields, respectively, and in 99% isomeric purity. Tetrahydropyran (1) was used as the starting material to obtain 5-bromopentanol (3) which was subsequently chain elongated to 7-(tetrahydropyran-2-yloxy)-1-heptyne (5) by the standard procedures. The organolithium compound from 5 was coupled with (Z)-1-bromo-4-nonene (11), obtained from the Wittig reaction between pentyltriphenylphosphonium bromide (9) and 4-(tetrahydropyran-2-yloxy)butanal (8) followed by bromination. The product, (Z)-1-(tetrahydropyran-2-yloxy)-11-hexadecen-6-yne (12) which resulted, was reduced with sodium/liquid ammonia to give 13 with the E-6 bond. Removal of the protecting group resulted in the desired alcohol 14 which on acetylation and oxidation gave the desired acetate 15 and the aldehyde 16, respectively.
Bio-inspired Total Synthesis of Twelve Securinega Alkaloids: Structural Reassignments of (+)-Virosine B and (?)-Episecurinol A
Antien, Kevin,Cossío, Fernando P.,Deffieux, Denis,Lacambra, Aitor,Massip, Stéphane,Peixoto, Philippe A.,Pouységu, Laurent,Quideau, Stéphane
supporting information, (2019/08/21)
The so-called Securinega alkaloids constitute a class of tetracyclic biologically active specialised metabolites isolated principally from subtropical plants belonging to the Phyllanthaceae family. Following a strategy based on alternative hypotheses for their biosynthesis, an easy and time-efficient divergent synthesis enabled access to twelve of those alkaloids featuring (neo)(nor)securinane skeletons. Moreover, this work permitted to reassign the absolute configurations of (+)-virosine B and (?)-episecurinol A.
Electronically Mismatched Cycloaddition Reactions via First-Row Transition Metal, Iron(III)-Polypyridyl Complex
Shin, Jung Ha,Seong, Eun Young,Mun, Hyeon Jin,Jang, Yu Jeong,Kang, Eun Joo
supporting information, p. 5872 - 5876 (2018/09/25)
The iron(III)-polypyridyl complex and its derivatives showed sufficient oxidizing potential to act as a one-electron oxidant, producing radical cations from olefins and promoting the efficient radical cation [2 + 2] and [2 + 4] cycloaddition reactions. Subsequent chain propagation afforded trisubstituted cyclobutane or cyclohexene derivatives, and this facile route enables the replacement of rare metals with sustainable, green, and inexpensive iron in radical cation cycloadditions.
FLUOROALKYLATING AGENT
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Paragraph 1495-1496, (2018/01/11)
Problem to be Solved It is intended to provide an industrially preferable fluoroalkylating agent and use thereof. Solution The present invention provides a fluoroalkylating agent represented by the general formula (1) wherein R1 is a C1 to C8 fluoroalkyl group; R2 and R3 are each independently a C1 to C12 alkyl group or the like; Y1 to Y4 are each independently a hydrogen atom, a halogen atom, or the like; and X? is a monovalent anion. A compound of the general formula (3): R4—S—R1 having an introduced C1 to C8 fluoroalkyl group is easily obtained by reacting a compound of the general formula (2): R4—S—Z wherein R4 is a hydrocarbon group or the like; and Z is a leaving group, with the compound of the general formula (1).
Tandem Pd-catalyzed C-C coupling/recyclization of 2-(2-bromoaryl)cyclopropane-1,1-dicarboxylates with primary nitro alkanes
Mikhaylov, Andrey A.,Dilman, Alexander D.,Novikov, Roman A.,Khoroshutina, Yulia A.,Struchkova, Marina I.,Arkhipov, Dmitry E.,Nelyubina, Yulia V.,Tabolin, Andrey A.,Ioffe, Sema L.
supporting information, p. 11 - 14 (2015/12/23)
The first successful synthesis of 1H-2,3-benzoxazine 3-oxides has been described. The efficiency of the approach is provided by the C-C-coupling of 2-(2-bromoaryl)cyclopropane-1,1-dicarboxylates with primary nitroalkanes catalyzed by Pd(dba)2/JohnPhos system followed by in situ recyclization of the intermediates. Several representative transformations allowing selective modification of the nitronate as well as malonate functionalities in the resulting compounds are demonstrated.
Ionic liquids as reaction media for esterification of carboxylate sodium salts with alkyl halides
Brinchi,Germani,Savelli
, p. 2027 - 2029 (2007/10/03)
Ionic liquids based on 1,3-dialkylimidazolinium methanesulfonate have been used as effective reusable reaction media in the esterification of several carboxylate sodium salts with different alkyl halides. Products are easily isolated by extraction with ether, and the protocol is mild and green, compared to the existing methods based on toxic solvents. Proper 'design' of the ionic liquid allows us to obtain esters always in quantitative yields.
Graphite-catalyzed acylative cleavage of ethers with acyl halides
Suzuki, Yoshitada,Matsushima, Masayuki,Kodomari, Mitsuo
, p. 319 - 320 (2007/10/03)
Graphite is found to catalyze acylative cleavage of ethers such as benzylic, allylic, tert-butylic and cyclic ethers with acyl halides to give the corresponding esters in good to excellent yields. Benzylic ether was cleaved chemoselectively, when a variety of other functional groups was present, to produce the corresponding ester along with benzyl halide.
Anti-androgenic cyclo and bicyclo alkenes
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, (2008/06/13)
Compounds having the formula (i), (ii) and (iii), STR1 where R is H, alkyl of 1 to 6 carbons, or CO--R 2 where R 2 is alkyl of 1 to 6 carbons; R 1 is H, CH 3, or (CH 2) m --CH 3 ; n is an integer having the values of 2 to 10, m is an integer having the values of 1 to 6, have anti-androgen activity on secondary androgen receptor sites. The compounds are useful for treating mammals, including humans afflicted with acne, male pattern baldness, adhesions and keloids. The compounds are also effective for treating other diseases or conditions which are related to androgen receptors, such as undesirable formation of breast capsules in females after breast augmentation surgery, osteoarthritis and symptoms of Alzheimer''s disease. The compounds also have inhibitory effect on the metabolism of certain microorganisms and fungi of the kind, the metabolism of which is normally known to be controllable by anti-androgen compounds.
Total synthesis of patulolide C and its homo, nor, and iso analogs
Leemhuis,Thijs,Zwanenburg
, p. 7170 - 7179 (2007/10/02)
The stereospecific total synthesis of the naturally occurring macrolide patulolide C 19Eb as well as its iso, nor, and homo analogs is described by applying the photoinduced rearrangement of enantiomerically pure epoxy diazomethyl ketones 14 to γ-hydroxy α,β-unsaturated esters 15 as the key step. The required epoxy diazomethyl ketones 14 are obtained by a Sharpless epoxidation of an appropriate allylic alcohol, followed by ruthenium tetraoxide oxidation to an oxiranecarboxylic acid, conversion into amixed anhydride, and treatment with diazomethane. Macrolide 19Zb, which is a geometrical isomer of 19Eb, turned out to be a diastereomer of natural macrolide isopatulolide C, which implies the 4R,11R configuration for this natural material. X-ray diffraction analyses of 19Ea and 19Eb show that there is a considerable difference in spatial arrangement; particularly, the different torsion angles between the carbonyl and olefinic bonds are noteworthy. The conformational behavior of these macrolides is also deduced from the NMR and UV spectra.
Synthesis of the leukotriene antagonist ablukast
Manchand,Micheli,Saposnik
, p. 9391 - 9398 (2007/10/02)
An efficient synthesis of the leukotriene antagonist ablukast (5) has been achieved starting from 2,4-dihydroxyacetophenone. The latter, on a Claisen condensation with ethyl oxalate, followed by hydrogenation, gave the chromane ester 7, which was subjected to a Fries rearrangement (AcOH/BF3·OEt2) and the product, after transesterification with methanol, was alkylated with 5-bromo-1-pentanyl acetate to afford the acetate 9. A novel methanolysis of 9 with methanol in the presence of tetra-n-butylammonium hydroxide followed by mesylation of the derived alcohol furnished the mesylate 10. Alkylation of the acetophenone derivative 16 with 10 using K2CO3 in the presence of tris(3,6-dioxaheptyl)amine and saponification gave 5.