16644-98-7Relevant articles and documents
Preparative singlet oxygenation of linoleate provides doubly allylic dihydroperoxides: Putative intermediates in the generation of biologically active aldehydes in vivo
Zhang, Wujuan,Sun, Mingjiang,Salomon, Robert G.
, p. 5607 - 5615 (2006)
Photoinduced oxygenation generates biologically active, oxidatively truncated lipids in the retina. Previously, doubly allylic dihydroperoxides, 9,12-dihydroperoxyoctadeca-10,13-dienoic acid (9,12-diHPODE) and 10,13-dihydroperoxyoctadeca-8,11-dienoic acid (10,13-diHPODE), were postulated as key intermediates in the free radical-promoted oxidative fragmentation of linoleate that generates aldehydes, such as the cytotoxic γ-hydroxyalkenal 4-hydroxy-2-nonenal (HNE), in vivo. We now report an efficient preparation of regioisomerically pure 9,12- and 10,13-diHPODE, devised to enable studies of their fragmentation reactions. Free radical-induced oxygenation of linoleate initially generates conjugated monohydroperoxy octadecadienoates (HPODEs) that are then converted into diHPODEs. In contrast, we found that singlet oxygenation of conjugated HPODEs does not produce diHPODEs. Unconjugated HPODEs are unique products of singlet oxygenation of linoleate that are coproduced with conjugated HPODEs. Preparative separation of the mixture of regioisomeric mono and diHPODEs generated by singlet oxygenation of linloeate is impractical. However, a simple tactic circumvented the problem. Thus, selective conversion of the undesired conjugated HPODEs into Diels-Alder adducts could be accomplished under mild conditions by reaction with N-phenyltriazolinedione. These adducts were readily removed, and the two remaining unconjugated HPODEs could then be easily isolated regioisomerically pure. Each of these was subsequently converted into a different, regioisomerically pure, diHPODE through further singlet oxygenation.
Total Synthesis of Natural Bicyclic Lactones (+)-Dihydrocanadensolide, (±)-Avenociolide, and (±)-Isoavenociolide via Tungsten-π-Allyl Complexes
Chen, Ming-Jung,Narkunan, Kesavaram,Liu, Rai-Shung
, p. 8311 - 8318 (1999)
A synthetic method using tungsten-π-allyl compounds is developed for total syntheses of natural bislactones including (+)-dihydrocanadensaolide (2), (±)-avenociolide (3), and (±)-isoavenociolide (4). Syntheses of these natural compounds are based on a com
STEREOSPECIFIC SYNTHESIS OF (Z)-13-HEXADECEN-11-YN-1-YL ACETATE THE SEX PHEROMONE OF THE PROCESSIONARY MOTH, AND OF (5Z,7E)-5,7-DODECADIEN-1-OL, A SEX PHEROMONE COMPONENT OF THE FOREST TENT CATERPILLAR
Rossi, Renzo,Carpita, Adriano
, p. 287 - 290 (1983)
(Z)-13-hexadecen-11-yn-1-yl acetate (2), the sex pheromone of Thaumetopoea pytyocampa, and (5Z,7E)-5,7-dodecadien-1-ol (3), sex pheromone component of Malacosoma disstria, have been prepared in high chemical and stereoisomeric purity by synthetic schemes involving the stereospecific coupling of ω-functionalized 1-alkynes with (Z)- or (E)-1-iodo-1-alkenes in the presence of a catalytic amount of (PPh3)4Pd and CuI, under phase transfer conditions.
Stereoselective Csp3?Csp2 Cross-Couplings of Chiral Secondary Alkylzinc Reagents with Alkenyl and Aryl Halides
Skotnitzki, Juri,Kremsmair, Alexander,Keefer, Daniel,Gong, Ye,de Vivie-Riedle, Regina,Knochel, Paul
supporting information, p. 320 - 324 (2019/11/26)
We report palladium-catalyzed cross-coupling reactions of chiral secondary non-stabilized dialkylzinc reagents, prepared from readily available chiral secondary alkyl iodides, with alkenyl and aryl halides. This method provides α-chiral alkenes and arenes with very high retention of configuration (dr up to 98:2) and satisfactory overall yields (up to 76 % for 3 reaction steps). The configurational stability of these chiral non-stabilized dialkylzinc reagents was determined and exceeded several hours at 25 °C. DFT calculations were performed to rationalize the stereoretention during the catalytic cycle. Furthermore, the cross-coupling reaction was applied in an efficient total synthesis of the sesquiterpenes (S)- and (R)-curcumene with control of the absolute stereochemistry.
One-Shot Radical Cross Coupling Between Benzyl Alcohols and Alkenyl Halides Using Ni/Ti/Mn System
Suga, Takuya,Takahashi, Yuuki,Ukaji, Yutaka
supporting information, p. 5622 - 5626 (2020/10/22)
A “one-shot” cross coupling between benzyl alcohols and alkenyl halides has been established. A combination of low-valent Ti-mediated C?OH homolysis and the prominent chemistry of Ni-based radical catalysis afforded the desired cross-coupled product with good efficiency. The reaction proceeded regardless of the electronic property of benzyl alcohols, and Ar?B bond remained intact throughout the reaction. Alkenyl bromides with various substitution patterns were applicable to this reaction. Attempts for utilizing sterically demanding tri-substituted alkenes indicated that the steric hinderance mainly inhibited the radical-trapping by Ni species. This reaction can be a simple and efficient strategy for synthesizing densely substituted allylbenzene derivatives. (Figure presented.).
Reactions of perfluorinated alkenyl-, alkynyl-, alkyltrifluoroborates, and selected hydrocarbon analogues with the halogenating agents Hal2 (Hal = F, Cl, Br), "brF" (BrF3-Br2 1:1), and ICl
Bardin, Vadim V.,Adonin, Nicolay Yu.,Frohn, Hermann-Josef
experimental part, p. 565 - 579 (2012/05/20)
Reactions of [Bu4N][RBF3] [R = CnF 2n+1CF=CF (cis, trans), CF2=CF, CF2=C(CF 3), trans-C4H9CF=CF, trans-C6H 5CF=CF, C4H9CH=CH (cis, trans), CF 3C≡C, and C4H9C≡C] with chlorine, bromine, BrF3 + Br2 (as equivalent of "BrF"), and ICl in solution (CH2Cl2, CHCl3, CF 3CH2CF2CH3) led to 1, 2-addition of halogen and/or replacement of boron by halogen (halodeboration). The reaction of [Bu4N][CF3C≡CBF3] with less than equimolar amounts of diluted fluorine (5 %) in 1, 1, 1, 3, 3-pentafluorobutane (PFB) showed only [Bu4N][CF3CF2CF 2BF3] as fluorine addition product besides extensive fluorodeboration. Suspensions of the insoluble K[CF2=CFBF 3] salt reacted with Cl2 and Br2 in CH 2Cl2 giving preferentially products of halogen addition across the C=C bond. In reactions with ICl iododeboration with formation of CF2=CFI occurred besides 1, 2-addition with formation of [CF 2I-CFClBF3]-. The halodeboration reaction of[Bu4N][trans-C4H9CF=CFBF3] with Br2, "BrF", and ICl, of K[trans-C6H 5CF=CFBF3] with Br2, and of [Bu 4N][trans-C4F9CF=CFBF3] with ICl proceeded stereospecifically. Copyright
