Chemistry of renieramycins. Part 6: Transformation of renieramycin M into jorumycin and renieramycin J including oxidative degradation products, mimosamycin, renierone, and renierol acetate

The transformation of renieramycin M (1m) into renieramycin J (1j) and jorumycin (2) is presented along with the results of antiproliferative assay data. The chemical stability and the oxidative degradation of 2 and renieramycin E (1e) to generate simple isoquinoline alkaloids, such as mimosamycin (7), renierol acetate (12), and renierone (8) are also described.     

Novel synthesis of the 2-azaanthraquinone alkaloid, scorpinone, based on two microwave-assisted pericyclic reactions

The total synthesis of the 2-azaanthraquinone alkaloid, scorpinone (4), isolated from the mycelium of a Bispora-like tropical fungus, has been completed in nine steps. The two key steps involve a microwave-assisted thermal electrocyclic reaction for the synthesis of an 8-oxygenated isoquinoline skeleton from a 1-aza 6π-hexatriene system, and a regioselective microwave-assisted [4+2] cycloaddition for the construction of a 2-azaanthraquinone framework.     

Synthesis and reactivity of some imidazo‐, triazolo‐ and tetrazolo‐isoquinoline derivatives

1‐Acetylirrüno‐3‐methyl‐1H‐isochromene‐4‐carbonitrile, 1 , reacts with glycine ethyl ester under basic conditions to give an imidazo[2,1‐a]isoquinoline derivative, while reaction with hydrazine hydrate in 1,4‐dioxane, with further chemistry, provides access to [1,2,4]triazolo[5,1‐a]isoquinoline, [1,2,4]triazolo[3,4‐a]isoquinoline and tetrazolo[5,1‐a]isoquinoline analogs. Benzene ring nitration and radical bromination of substituent methyl groups were investigated in the four tricycles, with some different positional reactivities being found. Two bromomethyl derivatives so produced were oxidised; ethyl 2‐bromomethyl‐6‐cyano‐5‐methylimidazo[2,1‐a]isoquinoline‐3‐carboxylate gave the anticipated ethyl 6‐cyano‐2‐formyl‐5‐methylimidazo[2,1‐a]isoquinoline‐3‐carboxylate (which reacted further with hydrazine to form a new system, 8,9‐dihydro‐6‐methyl‐8‐oxopyridazino[4′,5′:4,5]imidazo[2,1‐a]isoquinoline‐5‐carbonitrile), while 5‐bromomethyl‐2‐methyl[1,2,4]triazolo[5,1‐a]isoquinoline‐6‐carbonitrile unexpectedly gave directly another new system, 5,6‐dihydro‐5‐hydroxy‐2‐methyl‐7H‐pyrrolo[3,4‐c][1,2,4]triazolo[5,1‐a]isoquinolin‐7‐one.     

Diastereoselective synthesis of spiro-functionalized tetraalkyl benzoisoquinopyrrolonaphthyridine-tetracarboxylates from isoquinoline, dialkyl acetylenedicarboxylates, and indane-1,3-dione

An effective route to spiro-functionalized fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline, dialkyl acetylenedicarboxylates, and indane-1,3-dione.     

1 - 烃基异喹啉Reissert Compounds 的合成及其氢化研究

1-苄基异喹啉Reissertcompound经RaneyNi(w-2)催化氢化,分离得到二个未见报道的氢化产物,经化学和波谱分析推定其结构为:1-亚氨基-1-苄基-2-苯甲酰基-1,2-二氢异喹啉(4)和3-苯基-10b-苄基-1,10b-二氢咪唑骈[5,1-a]异喹啉(5)。据此提出了一条1-苄基异喹啉Reissertcompound高压催化氢化的途径,并对异喹啉eissertcompound高压催化氢化反应中酰基转位进行了讨论。试图以环已基溴作为烷化剂,在氢化钠条件下,与异喹啉Reissertcompound作用来制备1-环已基异喹啉Reissertcompound,结果只得到了1-氰基异喹啉,产率达75%,为制备1-氰基异喹啉提供了一个新方法。     

Some aspects of quantification of neutral steroid metabolites in body fluids of healthy and uremic subjects by capillary gas chromatography

Neutral steroid metabolites enriched from urine and hemofiltrate were identified by gas chromatography/mass spectrometry and quantified by capillary gas chromatography. This study included 20 healthy controls and 37 uremic patients. Before enrichment of steroids from biological material, the standard deviation of the workup procedure and subsequent derivatization into the trimethylsilyl-enol-trimethylsilyl ethers was tested and found to be 2–5% in urine and 12–17% in the more complicated workup procedure of hemofiltrate, but essentially smaller than the biological standard deviation. Compared to the 24 h urinary excretion rates of controls, the excretion rates of androsterone, etiocholanolone, and corticoid metabolites were significantly lower in uremic body fluids, while those of 11-oxygenated androstanolones, degradation products of corticoids, were enhanced in uremic urine. The ratio of corticoid metabolites to 11-oxygenated androstanolones in urine of nondialyzed uremics correlated significantly with their plasma creatinine levels.     

Psilocin analogs. III. Synthesis of 5-methoxy- and 5-hydroxy-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indoles

A number of tetrahydro-β-carbolines were prepared with oxygen substituents at C-5. This class of compounds represents a hybrid between two naturally occurring groups of hallucinogenic molecules, the 4-hydroxytryptamines and the 6- and 7-oxygenated β-carbolines.     

Total assignment of the 1H and 13C NMR spectra of pyrrolizino-[3,4,5-a,b]isoquinoline,benzo[1,2]pyrrolizino[3,4,5-a,b]isoquinoline and 2-methylthiopyrrolizino[3,4,5-a,b]isoquinoline

The total ¹H and ¹³C nmr spectral assignments of pyrrolizino[3,4,5-a,b]isoquinoline, benzo-[1,2]pyrrolizino[3,4,5-a,b]isoquinoline and 2-methylthiopyrrolizino[3,4,5-a,b]isoquinoline are reported. The concerted use of the COSY, HMQC, HMBC and nOe-difference experiments is used to generate total assignments of the ¹H and ¹³C nmr spectra.     

First total synthesis of a novel monoterpenoid isoquinoline alkaloid, (+/-)-alangine

The structure including the stereochemistry of a novel monoterpenoid isoquinoline alkaloid, alangine, was confirmed by total synthesis via N-acyliminium cyclization to construct the isoquinoline skeleton and reductive cleavage of vinyl epoxide with Pd(0) catalyst.     

First total synthesis of the 7-oxygenated carbazole alkaloids clauszoline-K, 3-formyl-7-hydroxycarbazole, clausine M, clausine N and the anti-HIV active siamenol using a highly efficient palladium-catalyzed approach

Using a convergent palladium-catalyzed construction of the carbazole framework as the key step we have achieved a short synthesis of the 7-oxygenated carbazole alkaloids clauszoline-K, 3-formyl-7-hydroxycarbazole, clausine C (clauszoline-L), clausine M, clausine N and the anti-HIV active siamenol.     

5-羟基-3,4-二氢异喹啉-1-酮的合成

以异喹啉为起始原料,经成盐、磺化得异喹啉-5-磺酸(3),3与熔融的氢氧化钠和氢氧化钾反应得1,5-二羟基异喹啉(4),以5%Pd-C为催化剂还原4得5-羟基-3,4-二氢异喹啉-1-酮(1),总收率47.6%。1的结构经1H NMR和MS确证。     

Nature of reissert analogs derived from N,N-dialkyl and N,N-diaryl carbamoyl chlorides

Reissert analogs were prepared from the reaction of isoquinoline and phthalazine with carbamoyl chlorides and cyanide using the methylene chloride-water method. Alkylation, condensation, Michael addition, and hydrolysis reactions of these Reissert analogs have been studied and found in many cases, to be similar to those of the isoquinoline Reissert compound.     

Diastereoselective allylzincation of γ-oxygenated vinyllithiums bearing functionalized side-chains

Allylzincation of γ-oxygenated vinyllithiums bearing functionalized side-chains proved to be more difficult than that reported in the case of γ-oxygenated vinyllithiums with unfunctionalized side-chains. However, when allylzincation occurs it gives the corresponding linear compounds with high diastereoselection as a consequence of the zinc being coordinated by the two oxygen atoms of the methoxymethyl ether moiety.     

Construction of Cationic Azahelicenes: Regioselective Three-Component Annulation Using In Situ Activation Strategy

Described herein is a strategy to construct cationic azahelicenes through the three-component annulation reaction of isoquinoline, indole, and 1,2-dichloroethane (DCE), in which DCE serves as an in situ activating agent for C1−H activation of isoquinoline, a vinyl equivalent, and a solvent. This in situ activation annulation reaction features a facile one-step synthesis and complete regioselectivity. The complete regioselectivity of C1 over C3 for the isoquinoline ring paves a path to the helical structure in a highly ordered sequence. One of the synthesized ionic [5]azahelicenium fluorophores exhibits the potential to serve as a mitochondria-targeted biomarker with good photostability and low cytotoxicity.     

Tandem synthesis of functionalized hexaalkyl benzoisoquinolinopyrrolonaphthyridine-hexacarboxylate,via isoquinoline based multi-component reaction

An expedient,synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline,dialkyl acetylenedicarboxylates and dialkyl chloromalonate.     

Synthesis of 19-oxygenated 4beta,5beta-epoxy derivatives of 16alpha-hydroxyandrostenedione as mechanistic and catalytic probes for aromatase reaction

4Beta,5beta-epoxy derivatives of 16alpha-hydroxyandrostenedione (2), one of the natural substrates for aromatase, and its 19-oxygenated compounds 4 and 5 were synthesized as mechanistic and catalytic probes for the enzyme reaction. Treatment of 16alpha-bromoandrostenedione (13) or its 19-hydroxy analog 19 which was prepared from 3beta-hydroxy-19-(tert-butyldimethylsiloxy)androst-5-en-17-one (16) in three steps, with H2O2 and NaOH followed by controlled alkaline hydrolysis with NaOH in aqueous pyridine stereospecifically yielded 4beta,5beta-epoxy-16alpha-ol 15 or 4beta,5beta-epoxy-16alpha,19-diol 22, respectively. Oxidation of 16beta-bromo-4beta,5beta-epoxy-19-ol 21 with pyridinium dichromate followed by controlled alkaline hydrolysis produced 4beta,5beta-epoxy-16alpha-hydroxy-19-al 24.     

The biosynthesis of cularine

The incorporation of the 7,8-oxygenated benzylisoquinoline into cularine ( ) is demonstrated.     

Stereoselective synthesis of (−)-malyngolide, (+)-malyngolide and (+)-tanikolide using ring-closing metathesis

The stereoselective syntheses of the naturally occurring δ-lactones (+)-tanikolide and (−)-malyngolide as well as of the unnatural (+)-enantiomer of the latter are described. Key steps in each of these syntheses were stereoselective additions of organometallic reagents to α-oxygenated ketones and olefin ring-closing metatheses.     

A novel multicomponent reaction involving isoquinoline,allenoate and activated ketone

The reaction of isoquinoline and allenoate with activated ketone resulted in a novel three component reaction, affording [1,3]oxazino[2,3-a]isoquinoline derivatives in moderate yields along with moderate diastereoselectivities via 1,4-dipolar cycloaddition. It was also found that when isatins were used as substrates, the regioselectivity of cycloadducts was different from those using ethyl trifluoropyruvate as substrate.     

Tandem synthesis of 1-(alkylamino)-2,4-diarylpyrimido[6,1-a]isoquinolin-5-ium chlorides from isoquinoline, N-alkyl-benzimidoyl chlorides, and isocyanides

1-(Alkylamino)-2,4-diarylpyrimido[6,1-a]isoquinolin-5-ium chlorides are obtained in good yields via a tandem reaction between isoquinoline, N-alkyl-benzimidoyl chlorides and alkyl isocyanides in anhydrous acetonitrile.