Preparation,molecular structures,and characteristic properties of (E)-1-(2-furyl)- and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylenes and (E)-1-(3-furyl)- and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylenes

Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also.     

Synthesis and Crystal Structure of 1-（Trifluoromethyl）-1-（propioloyl）-（E）-3-oxo-（2-thienyl）-（2-naphthylamine）

1INTRODUCTIONTheSchiffbasesderivedfromb-diketonesandaliphaticamineshavebeenshowntoexistastheketo-amines.However,ifsubstituentseitherattheketooraminogrouparearomatic,itmaybeexpectedtheenoliminewillbethefavoredtautomericform[1].Recently,someSchiffbasesderivedfromTTA(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione)andPMBPhavebeenstudiedbyWang[2]andYu[3]etal.Inordertostudytherelationshipbetweenthestructuresandperformancesofthesecompounds,thetitlecom-poundwillbereportedherein.2EXPERIMENT…     

Total syntheses of beta-carboline alkaloids, (R)-(-)-pyridindolol K1, (R)-(-)-pyridindolol K2, and (R)-(-)-pyridindolol.

The total syntheses of beta-carboline alkaloids, (R)-(-)-pyridindolols (1, 5, and 6) are described. The two key steps involved are (1) a thermal electrocyclic reaction of the 3-alkenylindole-2-aldoxime 10 and (2) a thermal cyclization of 3-alkynylindole-2-aldoxime 11 to construct the beta-carboline N-oxides 8, which upon heating with acetic anhydride and sequential treatment with trifluoromethanesulfonic anhydride gave the triflates 18. The Stille coupling reaction of 18 with vinylstannane, followed by cleavage of MOM ether, afforded the 1-ethenyl-3-hydroxymethyl-beta-carboline (7a). Subsequent acetylation of 7a yielded the acetate 7b, which was subjected to the Sharpless asymmetric 1,2-dihydroxylation by AD-mix-beta to produce (R)-(-)-pyridindolol K2 (6). Selective acetylation of 6 was effected by Ac(2)O and collidine to form (R)-(-)-pyridindolol K1 (5). By contrast, hydrolysis of 6 provided (R)-(-)-pyridindolol (1).     

Total synthesis of (S)-(+)-curcudiol, and (S)-(+)- and (R)-(-)-curcuphenol.

A highly enantioselective synthesis of the versatile chiral synthons possessing one stereogenic center, (S)- and (R)-4-aryl-5-hydroxy-(2E)-pentenoate (3) was achieved based on the enzymatic reaction of (+/-)-3 with commercially available lipases MY-30 or OF-360 from Candida rugosa. Application of (S)-3 and (R)-3 to the total syntheses of(S)-curcuphenol (1), (S)-curcudiol (2), and (R)-curcuphenol (1), respectively, is described.     

Synthesis and Molecular Structure of (E)-1-(Morpholino)-2-(thiomethyl)-2-phenylvinylphosphonate

1 INTRODUCTION Phosphorus-containing vinyl compounds havebeen widely studied due to their versatile physiolo-gical activities and applications in transition metalchemistry, asymmetric catalysis and photorearrange-ment[1～4]. In our previous papers, we have reportedthe syntheses of 2,2,4,5-tetrasubstituted-1,3-dithio-les[5] and 2,5-bis(morpholino)-3,4-bis-(p-chloro-phe-nyl)thiophenes[6] by the reactions of α-thioaroyl-thiofor-mamide with trimethyl phosphite at room tempera-ture and in refl…     

Reaction of (R)-(-)-2-aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato)platinum( II) with guanosine

The reaction of a new antitumor platinum complex, (R)-(-)-2-aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato++ +)platinum(II) (1) with guanosine at room temperature in an aqueous solution was followed by proton nuclear magnetic resonance (1H-NMR) spectroscopy and high performance liquid chromatography (HPLC) at intervals. Both techniques showed that a new compound was formed by displacement of the 1,1-cyclobutanedicarboxylate moiety of 1 with two guanosines, and its 1H-NMR spectrum and HPLC chromatogram were proved to be identical with those of [(R)-(-)-2-aminomethylpyrrolidine]bis(N7-guanosine)platinum(II) (2), which was obtained upon successive treatment of (R)-(-)-2-aminomethylpyrrolidinedichloroplatinum(II) (3) with AgNO3 and 2 mol eq of guanosine in water. The binding sites of the platinum to the two guanosine moieties in 2 were confirmed by the pH dependence of the two G-H8 signals.     

Synthesis of (-)-7-epiaustraline and (-)-1-epicastanospermine

Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-beta-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (-)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (-)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (-)-1-epicastanospermine was assured by single-crystal X-ray structure analysis of intermediate (-)-27a. Thus, the sign of the optical rotation had to be revised. The overall efficiency of these syntheses were 9 steps and 23% yield for (-)-7-epiaustraline and 10 steps and 20% yield for (-)-1-epicastanospermine     

Molecular rearrangements of (-)-modhephene and (-)-isocomene to a (-)-triquinane

The preparation and further rearrangement of (-)-modhephene (1) to a (-)-triquinane 5 has been assessed through acid catalysis. The rearrangement involved protonation, 1,2 sigma-bond and methyl shifts, and deprotonation. Monitored experiments by 1H NMR spectroscopy suggested the intermediate (-)-isocomene (3), which was further evidenced when a sample of natural (-)-3 undergoes acid-catalyzed conversion to the (-)-triquinane 5. In addition, deuterated (-)-modhephene (1-d) labeled stereospecifically at the 14beta geminal methyl group at C4 was synthesized, through the corresponding chiral deuterated primary alcohol, in 5 steps, starting from natural (-)-14-hydroxymodhephene (8), and rearranged under acid catalysis to elucidate the stereochemical factors that control the methyl shift at this position. The final deuterium-labeled (-)-triquinane, 5-d, obtained from [14-(2)H1]-1-d was established to have deuterium in the methyl group at C5 by 13C NMR spectroscopy. This stereoselective methyl migration is in accordance with the molecular orbital demand formulated by the quantum chemical calculations performed in the present study.     

Reversed-phase ion-pair high performance liquid chromatographic determination of Co(III)-, Ni(II)-, V(V)- and Fe(III)-2-(2-benzothiazolylazo)-5-(3-sulforpropyl)aminophenol chelates

The separation and determination of Co(III), Ni(II), V(V) and Fe(III) chelates with 2-(2-benzothiazolylazo)-5-(3-sulfopropyl)aminophenol (BTASPAP) by reversed-phase ion-pair HPLC was investigated. In the presence of the oxidant potassium iodate, BTASPAP reacts with Co(III), Ni(II), V(V) and Fe(III) to form stable, negatively charged, water-soluble chelates. The chelates were separated on a C(18) siloxane bonded phase and eluted within 7 min with acetonitrile-acetate-water (36:1:63 v/v) containing 0.2 mol 1(-1) acetic acid-sodium acetate buffer (pH 3.0) and 1.0 mmol 1(-1) tetrabutylammonium bromide. The detection limits of Co(III), Ni(II), V(V) and Fe(III) at 565 nm are 0.3, 0.8, 0.3 and 1.0 ng (signal-to-noise ratio = 2), respectively. The method was applied to the determination of Co, Ni, V and Fe in four samples of standard alloys.     

Total Syntheses of (-)-Papuamine and (-)-Haliclonadiamine

The pentacyclic marine alkaloids (-)-papuamine (1) and (-)-haliclonadiamine (2) have been prepared by total synthesis. The synthesis began with (-)-8, which was converted into diester 20 by way of bis-mesylate 17, dinitrile 18, and diacid 19. Dieckmann cyclization of 20 provided keto ester 21, which was transformed into acetal 22. After hydrolysis of the acetal, ketone 25 was subjected to reductive amination with 1,3-propanediamine and sodium triacetoxyborohydride to obtain diamines 26 and 27 as a 71:29 mixture of diastereomers, favoring the symmetrical isomer having the papuamine relative configuration. After transformation of the diamines to their t-Boc derivatives, the benzyl ethers were cleaved and the resulting diol was oxidized to dialdehyde 30. Application of the Seyferth procedure for conversion of aldehydes to alkynes gave a mixture of diynes 31 and 32. After removal of the t-Boc protecting groups from 31, diamino diyne 15 was treated with tributylstannane and azoisobutyronitrile to obtain the bis-vinylstannane 34. Treatment of this compound with Pd(II) and Cu(I) in the presence of air produced (-)-papuamine (1). (-)-Haliclonadiamine (2) was obtained from the unsymmetrical isomer, 32. The NMR spectra of the synthetic alkaloids were identical to those of authentic samples of the natural alkaloids.     

Straightforward synthesis of (R)-(-)-kjellmanianone

A direct route to enantiomerically pure (-)-kjellmanianone is reported. The synthesis involves a cerium-catalyzed alpha-hydroxylation and an enzyme-catalyzed procedure to resolve tertiary alcohols at key stages. The intermediate beta-oxo ester was alpha-hydroxylated to give good yields of racemic kjellmanianone. The resolution of the racemic material was achieved by enzymatic saponification, followed by a chemical decarboxylation sequence to give enantiopure (-)-kjellmanianone with 99 % ee. Bromination then afforded the (-)-bromo derivative, whose X-ray structure provided evidence for the R configuration of (-)-kjellmanianone.     

Novel (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles from (E)- and (Z)-3-styrylchromones: the unexpected case of (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles

An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations was discussed and the stereochemistry of all products was assigned by NMR experiments.     

Enantiocontrolled synthesis of (-)-9-epi-pentazocine and (-)-aphanorphine

We have developed novel asymmetric routes to (-)-9- epi-pentazocine and (-)-aphanorphine from a d-tyrosine derivative. The tricyclic frameworks of (-)-9- epi-pentazocine and (-)-aphanorphine were assembled stereoselectively via intramolecular Friedel-Crafts reaction of the corresponding bicyclic precursors, generated with titanium-promoted enyne cyclization and indium-initiated atom-transfer radical cyclization, respectively.     

Asymmetric total syntheses of (-)-antofine and (-)-cryptopleurine using (R)-(E)-4-(tributylstannyl)but-3-en-2-ol

The asymmetric total syntheses of the representative phenanthroindolizidine and phenanthroquinolizidine alkaloids, (-)-antofine and (-)-cryptopleurine, are described. An efficient synthetic pathway to the key intermediate 12, in enantiomerically pure form, was achieved by using a chiral building block (R)-9 and the Overman rearrangement with a total transfer of chirality. The problem of constructing the pyrrolidine and piperidine rings was successfully addressed, primarily by using a ring-closing metathesis reaction and a cross-metathesis reaction, respectively.     

Synthesis of 2-(Perfluoroalkylether)- and -(Perfluoroaryl) Benzothiazoles(su1)

Benzothiazoles containing 2-perfluoroalkylether as well as perfluoroaryl substituents have been synthesized by two methods: (1) direct acylation of 2-aminobenzenethiol with perfluoroacyl halides, and (2) the reduction of N, Nt?-diacy1-2, 2t?-diaminodiphenyldisulfides followed by dehydrative cyclization. The intermediates formed in the direct acylation procedure are the N-acylaminobenzenethiols rather than the S-acyl derivatives.     

The Synthesis and Structure of (1-(Diphenylphosphino)-1 - (Phenylthio)Ferrocene)Tricarbonyliron(O) (ptppf)Fe(CO)3

The complex (ptppf)Fe(CO)₃ has been prepared in high yield by the reaction of ptppf, l-(diphenyl-phosphino)-l'-(phenylthio)ferrocene, with (cis-cyclooctene)₂-Fe(CO)₃ in THF at ?60°C. The complex has been characterized by IR, ³¹P NMR, mass spectrometry and single-crystal X-ray diffraction. This compound is the first example of a ferrocenyl ligand having both sulfur and phosphorus donor atoms bound to a Fe(CO)₃ moiety. X-ray crystallography shows that the two cyclopentadienyl rings are approximately eclipsed, a rotation of 13° from exactly eclipsed conformation. The tricarbonyl iron center has a trigonal bipyramidal geometry with sulfur occupying the equatorial site and phosphorus the axial site. Crystals of (ptppf)Fe(CO)₃ are monoclinic, with a = 11.645(2), b = 14.304(1), c = 17.075(2) Å,β = 109.23(3)°, Z = 4, and space group P 2₁/n. The structure was solved according to the heavy-atom method and refined by full-matrix least-squares procedures to R = 0.037 for 2098 reflections with I ≥ 2.5σ(I).     

Synthesis and Crystal Structure of (E)-2-(1-(2-Hydroxy-4-methoxyphenyl)ethylideneamino)-3-(4-hydroxyphenyl)methyl Propionate

(E)-2-(1-(2-Hydroxy-4-methoxyphenyl)ethylideneamino)-3-(4-hydroxyphenyl)methyl propionate (C22H27O6N, Mr = 401.45) has been synthesized by a condensation reaction of paeonol with tyrosin methyl ester hydrochloride, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 11.91291(15), b = 9.49947(12), c = 19.8727(3) , β = 106.1104(15)°, V = 2160.60(5)3, Z = 4, Dc = 1.234 g/cm3, μ = 0.739 mm-1, F(000) = 856, R = 0.0466 and wR = 0.1461 for 3859 observed reflections with (Ⅰ> 2σ(Ⅰ)). In the crystal structure, the title compound is constructed by a centrosymmetric dimmer unit composed of a pair of π-π stacking enantiomers, and such units are linked by intermolecular O(5)-H(5)…O(1) and intramolecular N(1)-H(1)…O(1) hydrogen bonds.     

1-(Triorganylsilyl)-2-(triethoxysilyl)ethanes

Conclusions The conditions were found for the hydrosilylation of CH₂=CHSi(OC₂H₅)₃ with triorganylsilanes in the presence of H₂PtCl₆ · 6H₂O in isopropanol, which assured a high yield (>90%) of the 1-(triorganylsilyl)-2-(tri-ethoxysilyl)ethanes. These conditions were used to synthesize 27 new 1-(triorganylsilyl)-2-(triethoxysilyl)-ethanes.The addition of (C₂H₅O)₃SiH to (CH₂=CHSi(CH₃)₃ in the presence of the same catalyst gave 1-(trimethyl-silyl)-2-(triethoxysilyl)ethane in 98.6% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1622–1625, July, 1976.