75814-58-3Relevant academic research and scientific papers
Nickel-Catalyzed Decarboxylative Alkenylation of Anhydrides with Vinyl Triflates or Halides
Chen, Hui,Sun, Shuhao,Liao, Xuebin
supporting information, p. 3625 - 3630 (2019/05/24)
Decarboxylative cross-coupling of aliphatic acid anhydrides with vinyl triflates or halides was accomplished via nickel catalysis. This methodology works well with a broad array of substrates and features abundant functional group tolerance. Notably, our approach addresses the issue of safe and environmental installation of methyl or ethyl group into molecular scaffolds. The method possesses high chemoselectivity toward alkyl groups when aliphatic/aromatic mixed anhydrides are involved. Furthermore, diverse ketones could be modified with our strategy.
Synthesis of new trans double-bond sphingolipid analogues: Δ4,6 and Δ6 ceramides
Chun, Jiong,Li, Guoqing,Byun, Hoe-Sup,Bittman, Robert
, p. 2600 - 2605 (2007/10/03)
Unsaturation was introduced at Δ4,6 and Δ6 of the sphingoid chain of naturally occurring ceramide 1 via a β-keto sulfoxide (12) and sulfone (18) derived from N-Boc-L-serine methyl ester acetonide (9), affording two novel ceramide analogues, (2S,3R)-2-octanoylamidooctadeca-(4E,6E)-diene-1,3diol (2) and (2S,3R)-2-octanoylamidooctadec-(6E)-ene-1,3-diol (3). After C-alkylation of 12 with (E)1-bromo-2-tetradecene (8), a trans double bond was installed by elimination of PhS(O)H, providing conjugated dienone oxazolidine 13. Reaction of 18 with 8, followed by desulfonation (Al(Hg)), afforded keto-oxazolidine 20, which bears a (E)-Δ6 double bond. The syntheses of analogues 2 and 3 from ketones 13 and 20, respectively, were completed by the following sequence of reactions: diastereoselective reduction (NaBH4/CeCl3 or DIBAL-H), hydrolysis of the oxazolidine ring, liberation of the amino group, and installation of the N-amide group.
Syntheses of the Macrocyclic Spermine Alkaloids (+/-)-Budmunchiamine A-C
Popaj, Kasim,Hesse, Manfred
, p. 180 - 186 (2007/10/03)
The syntheses of four macrocyclic spermine alkaloids, (+/-)-budmunchiamine A-C (1a-c) and (+/-)-budmunchiamine L4 (1), were accomplished by Michael addition of spermine to the α,β-unsaturated esters 3a-d, followed by cyclization of the resulting α,ω-tetraamino esters 4a-d with triethoxyantimony; N-methylation of the amino lactams 6a-c yielded the budmunchiamines A-C (1a-c).
Wittig-type Reaction of Dimetallated Carbodianion Species as Produced by Zinc Reduction of gem-Polyhalogen Compounds in the Presence of Levis Acids
Takai, Kazuhiko,Hotta, Yuji,Oshima, Koichiro,Nozaki, Hitosi
, p. 1698 - 1702 (2007/10/02)
Treatment of R1COR2 with a suspension prepared from diiodomethane, trimethylaluminium and excess zinc in tetrahydrofuran at room temperature affords olefins R1R2C=CH2 in fair (R1,R2=alkyl) to good (R1=alkyl, R2=H) yields.The ketone methylenation is better carried with another system consisting of CH2Br2-Zn-TiCl4.Ketones and aldehydes are transformed into α-chloro α,β-unsaturated esters or α,β-unsaturated esters in good yields on treatment with methyl trichloroacetate or t-butyl dichloroacetate (ethyl dibromoacetate) in the presence of diethylaluminium chloride and zinc.
