Formal Total Synthesis of Aliskiren

The efficient and selective formal total synthesis of aliskiren is described. Aliskiren, a renin inhibitor drug, has received considerable attention, primarily because it is the first of the renin inhibitor drugs to be approved by the FDA. Herein, the formal synthesis of aliskiren by iridium‐catalyzed asymmetric hydrogenation of two allylic alcohol fragments is reported. Screening a number of N,P‐ligated iridium catalysts yielded two catalysts that gave the highest enantioselectivity in the hydrogenation, which gave the saturated alcohols in 97 and 93 % ee. In only four steps after hydrogenation, the fragments were combined by using the Julia–Kocienski reaction to produce late‐stage intermediate in an overall yield of 18 %.     

Total Synthesis of Siomycin A: Completion of the Total Synthesis

The total synthesis of siomycin A ( 1 ), a representative compound of the thiostrepton family of peptide antibiotics, was achieved by incorporating the five synthetic segments A ( 2 ), B ( 3 ), C ( 4 ), D ( 5 ), and E ( 6 ). The dehydropiperidine segment A ( 2 ) was esterified with the dihydroquinoline segment C ( 4 ), and the subsequent coupling with the β‐phenylselenoalanine dipeptide segment D ( 5 ) at the segment C portion followed by lactamization between the segments A and D gave segment A‐C‐D ( 27 ). This was amidated with the pentapeptide segment B ( 3 ) at the segment A portion followed by one‐pot cyclization (between segments A and B) and elongation (with the β‐phenylselenoalanine dipeptide segment E ( 6 ) at the segment A portion), thus furnishing siomycin A ( 1 ).     

Total Synthesis of Pagoamide A

The first total synthesis of the thiazole-containing cyclic depsipeptide pagoamide A, is detailed. The longest linear sequence of the liquid-phase synthesis comprises 9 long linear steps from simple known starting materials, which led to the unambiguous structural confirmation of pagoamide A.     

Total Synthesis of N-Methylsansalvamide A

Sansalvamide A is a cyclic depsipeptide, isolated from a marine fungus of the genus Fusarium by Belofsky in 19991. The depsipeptide displays cytotoxic and antiviral activities, and also possesses inhibitor of MCV topoisomerase2. The corresponding amide de…     

Total Synthesis of Gnetifolin A

GnetifolinAwasisolatedfromGnetumparrdolium(Wrt.)C.Y.ChengbyLietal.l1]ItsstructUrewasrevisedbycomtarisonofits1H-NMRdarewiththatofitSanalogS.l2l[3jAmodelsynthesisofananalogwith"inert"oxygenfunctionshasalsobeenrepodedinourlaboraory.I']InordertogiveadefinitiveconfirmationofitssmictUreandProvidemorequantityofsampleforfurtherbiologicalinvestigation,thetotalsynthesisofgnetifoIinAviaintraInolecularWittigreactionwasaccomplished.Herewereportthesyntheticroute.Themainprobleminthesynthesiswasthepr…     

Total Synthesis of Aetheramide A

The first total synthesis of the highly potent anti‐HIV natural product aetheramide A was accomplished in 18 steps from four equally complex building blocks. The synthesis established the unknown configuration at C26 and used a configurationally labile β‐ketoester moiety for the self‐adjustment of the configuration at a methyl branch. The pivotal macrolactamization was achieved by trapping a thermally generated acylketene which was derived from its corresponding dioxinone.     

Total Synthesis of Tricolorin A

Tricolorin A (1), a structurally amazing resin glycoside with promising bioactivities from Ipomoea tricolor cav. (convolvulaceae), was synthesized in a total of 45 steps, with the longest linear sequence of 20 steps and overall yield of 0.65% from D-mannitol. The AB disaccharide 19-membered lactone 2 was constructured by a regioselective macrolactonization using Corey-Nicolaou protocol. The macrolactone tetrasaccharide 33 was realized either by "one-pot two-step" glycosylation procedure or by a stepwise assembly employing the "armed-disarmed" glycosylation strategy.     

Ligudentatin A的全合成

以(+)-紫苏醇2为起始原料, 经氧化、Witting、Diels-Alder和烯酮的芳构化等反应, 最终以17.7%的总收率完成了去甲基倍半萜Ligudentatin A(1)的全合成, 其中Diels-Alder和烯酮的芳构化反应为关键步骤.     

Total Synthesis of Sanglifehrin A

The immunosuppressive agent sanglifehrin A has been prepared for the first time by total synthesis. The construction of the macrocyclic unit of the target molecule was achieved through a selective intramolecular Stille coupling, and the spirolactam unit by Paterson–aldol reactions. The final steps involve an intermolecular Stille coupling and the opening of the internal acetal unit. This convergent synthesis opens the way for the synthesis of libraries of novel sanglifehrin analogues for biological screening.     

A Total Synthesis of RA-VII

RA-VII (1) and related bicyclic hexapeptides, isolated from Rubiaceous plants, Rubia akame,showed potent antitumor activity and in fact, RA-VII is currently undergoing phase Ⅱ clinical trial in Japan. It inhibit protein synthesis through binding,to eukaryotic 80S ribosomes, resulting in inhibition of aminoacyl-tRNA binding formation and peptidyl-tRNA translocation. The complex molecular architecture and interesting biological activity made these compounds attractive synthetic targets.     

Total Synthesis of Calophyline A

Reported herein is the total synthesis of calophyline A, an indoline natural product possessing distinct ring connectivity which has not been synthesized previously. The synthetic route features several key transformations, including an aza‐pinacol rearrangement to construct the nitrogen‐containing bridged [3.2.2] bicycle, a Heck cyclization to assemble the fused 6/5/6/5 ring system, and a challenging late‐stage aldol reaction to generate both a neopentyl quaternary stereogenic center and an oxygen‐containing bridged [3.2.1] bicycle.     

仙茅素A的全合成

首次报道了仙茅素A[2,5-双(3,4-二羟基苯基)呋喃-3-甲醛]的全合成。以3,4-二甲氧基苯乙酮为起始原料,经Paal-Knorr反应,选择性溴代及还原等反应合成了仙茅素A,其结构经1H NMR,13C NMR和ESI-MS表征。     

A Total Synthesis of Isosolanone

Nitroaldol reaction of acetone with nitromethane in the presence of base to give a nitroalcohol 3, followed by acetylation, and subsequent reduction of the resultant acetate 4 with NaBH₄ gave 2-methyl-1-nitropropane 5. Michael reaction of 5 in base with acrylonitrile to give nitronitrile 6, and Nef conversion of the nitro group resulted in the corresponding ketonic nitrile 7. Wittig olefination of the ketonic nitrile with 3-methyl-2-butenyl triphenylphosphonium bromide 8 gave dienenitrile 9, which upon treatment with MeLi, followed by acidic work up, provided isosolanone 2.     

Total Synthesis of Machilin A

Machilin A 9, a natural diarylbutane-lignan, was isolated from the bark and root ofMachilus thunbergii Sieb. et Zucc., which was used in traditional Chinese madicine'.This kind of lignan has shown various bioactivities and attracted organic chemists a greatattention2' 3.i. KMnO., 70-80 "C, lh. 88%, n. SOCI,, 95 "C, iii. CH,COCH,COOEt/NaOEt, THF, reflux. tv.NH.CI. EtOH, reflux, (n, iii, tv overall yield 78%), v. l, / NaOEt, THF, 98%, yi. PTSA, Benzene.reflux, 84%, vii. LAH, …