Synthesis of a flav-3-en-3-ol via cinnamylphenol

Vinyl quinone methide ($\text{1}$) reacts with polyphenols to give cinnamylphenols ($\text{4}$) and neo-flavanoids ($\text{5}$). Oxidation of cinnamylphenol ($\text{4}$b) leads to malvidin ($\text{10}$) via the isolated intermediate flav-3-en-3o1 ($\text{8}$b).     

Pyrolysis of homoadamant-3-ene

Pyrolysis of homoadamant-3-ene ($\text{5}$), generated from 1-adamantylcarbene ($\text{7}$), leads to the same three olefins ($\text{2}$, $\text{3}$, and $\text{4}$) that are produced from pyrolysis of 3-homoadamantyl acetate ($\text{1}$).     

Transposition des oximies de la 2H-naptho [1,8-bc] pyrannone-3 et de la 2H-benzo [b] furannone-3

Refluxing the oximes ($\text{2}$) of naphtho-[1,8-bc] pyran-3(2H)-one and ($\text{6}$) of 3 (2H)-benzofuranone with alcoholic hydrogen chloride give the corresponding α-alkoxy-ketones $\text{3}$, $\text{4}$, $\text{5}$ and α-chloroketone $\text{7}$ respectively. This transformation appears to be related to the acid conversion of N-aryhydroxylamines to o. and p. substituted anilines (BAMBERGER réarrangement.     

Synthesis of 3-methylisoguanosine,a positional isomer of pharmacologically active nucleosides from marine animals

3-Methylisoguanosine ($\text{4c}$) has been synthesized from 5-(cyanomethylamino)-1(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazole-4-carboxamide ($\text{1b}$) through the carbonitrile ($\text{2b}$).     

Photocyclization of benzofurancarboxanilides. Photorearrangement of the benzodihydrofuran system to 3-o-hydroxyphenylquinolones

$\text{cis}$-Dihydrobenzofuro[2,3-c]quinolone ($\text{4a}$) and $\text{cis}$-dihydrobenzofuro-[3,2-c]quinolone ($\text{5}$) undergo photorearrangement, characteristic to the benzodihydrofuran system, leading to 3-$\text{o}$-hydroxyphenylquinolone ($\text{6}$). A plausible mechanism involving a cyclopropyl dienone ($\text{12}$) was discussed.     

Synthesis of the n-benzoyl derivatives of L-arabino,L-xylo and L-lyxo (L-vancosamine) isomers of 2,3,6-trideoxy-3-C-methyl-3-aminohexose from a non-carbohydrate precursor

The synthesis of the N-benzoyl derivatives of $\text{L}$-$\text{arabino}$ (10),$\text{L}$-$\text{xylo}$ (13) and $\text{L}$-$\text{lyxo}$ ($\text{L}$-vancosamine) (12) 2,3,6-trideoxy-3-$\text{C}$-methyl-3-aminohexose from the (2$\text{S}$,3$\text{R}$) diol (1) prepared in fermenting bakers' yeast from α-methylcinnamaldehyde and acetaldehyde is reported     

Adenosine cyclic 3′,5′-(RP)- and (SP)-phosphoramidates,the first representatives of nucleoside cyclic 3′,5′-phosphoramidates derived from ammonia

Adenosine cyclic 3′,5′-phosphoramidate $\text{2}$ was synthesized by reacting adenosine cyclic 3′,5′-phosphate $\text{1}$ with POCl₃, in trimethyl phosphate for 1 h at O°C, followed by in situ treatment of the reaction mixture with a suspension of (NH₄)₂CO₃ in anhydrous DMF or pyridine or DMF/pyridine mixture for 30 min at 25° C. Diastereoisomers ($\text{R}$_P)-$\text{2}$ and ($\text{S}$_P)-$\text{2}$ the relative quantities of which depended on the solvent of (NH₄)₂CO₃ treatment, were separated by reversed phase partition chromatography. Hydrolysis of (R_P)-$\text{2}$ and (S_P)-$\text{2}$ proceeded with predominant (90% in 0.1 N HCl, 100% in 0.1 N NaOH) -P-O-C bond breaking.     

Synthese de l'acide β fluoroacrylique (fluoro-3 propenoique)

Regioselective Bayer-Villiger oxidation of 2-chloro-2-fluoroethyl-isopropyl ketone ($\text{1}$) gives isopropyl-3-chloro-3 fluoropropionate ($\text{2}$). The dehalogenation of ester ($\text{2}$) with trimethylamine gives isopropyl-3-fluoropropenoate ($\text{3}$). Ester cleavage by trimethylsilyl iodide, in the presence of cyclohexene oxide, gives $\text{trans}$-3-fluoropropenoic acid ($\text{4}$).     

Dinuclear iron carbonyl complexes of 3H-1,2-diazepines

3H-1,2-Diazepines ($\text{1}\text{2}$) give dinuclear complexes ($\text{3}\text{4}$) on reaction with diiron nonacarbonyl. Complexation much reduces the rate of the [1,5] sigmatropic hydrogen shift across the diazepine ring and also reduces the activation energy for ring inversion.     

Efficient syntheses of naturally occurring 3,4-dihydroxyprolines: Electrophile-mediated lactonization of 2-amino-3-hydroxy-4-pentenoic acid derivatives

Stereospecific conversion of β-hydroxyallylglycine derivatives into (2$\text{S}$, 3$\text{R}$, 4$\text{R}$) 1 and (2$\text{S}$, 3$\text{S}$, 4$\text{S}$) 2 $\text{via}$ halo- or mercuri-lactonization has been described.     

Reaction of 3-azido-5-phenyl-1,2,4-oxadiazole with dimethylformamide,a new deoxygenative coupling reaction

When 3-bromo-5-phenyl-1,2,4-oxadiazole (1b) is heated with sodium azide in anhydrous dimethylformamide at 130°, 3-dimethylamino-($\text{1c}$) and 3-dimethylaminomethyleneamino-5-phenyl-1,2,4-oxadiazole ($\text{1d}$) are formed, the latter by a new deoxygenative coupling of the azide ($\text{1a}$), or the nitrene derived from it, with the solvent.     

1-methyl-(D3)-trishomocubane

The acid catalysed rearrangement of 8-methyl-pentacyclo(5.4.0.0^2,6.0^3,10.0^5,9)undecan-8-endo-o1 ($\text{8}$) to 3-methyl-(D₃)-trishomocuban-4-o1 ($\text{9}$) provided the key step to the synthesis of the title compound ($\text{11}$).     

Perfluoroalkyl derivatives of nitrogen. Part LI [1]. Reaction of the N-halogenobistrifluoromethylamines (CF3)2NX (X=Cl,Br) with norbornadiene

Reaction of the amines (CF₃)₂NX (X=Cl,Br) with norbornadiene either in solvent (CH₂Cl₂) at ?78 °C in the dark or in the vapour phase at 20 °C in daylight gives a mixture of 3-halogeno-5-($\text{NN}$-bistrifluoromethylamino)nortricyclene ($\text{exo}$, $\text{endo}$-and $\text{exo}$, $\text{exo}$-isomers) and $\text{exo}$-5-($\text{NN}$-bistrifluoromethylamino)- $\text{anti}$-7-halogenonorbornene in quantitative yield formed $\text{via}$ halonium ion addition to the diene. The reaction of the amine (CF₃)₂NBr in solvent Me₂O or Et₂O at ?78 °C in the dark gives the same products in low yield, together with 3-bromo-5-alkoxynortricyclene ($\text{exo}$, $\text{endo}$- and $\text{exo}$, $\text{exo}$-isomers) and the amine (CF₃)₂NR (R=Me, Et) in high yield.     

Cis-trihetero-tris-σ-homobenzenes as tridentate ligands - X-ray crystal. Structure analyses of the Co(C6H9N3)2(NO3)3 and Ba(C6H6O3)4(ClO4)2-complexes

According to X-ray crystal structure analyses “cis-benzenetrisimine” ($\text{2}$) and “cis-benzenetrioxide” ($\text{1}$) act as tridentate ligands in their 2:1- and 4:1-complexes $\text{7}$ (Co(C₆H₉N₃)₂(NO₃)₃) and $\text{8}$ (Ba(C₆H₆O₃)₄(ClO₄)₂), resp. The latter is the rare example of an organic complex with the (approximate) T-symmetry.     

The octant rule. XVI1. COnformation and circular dichroism of syn and anti 2-methylbicyclo[3.1.0]hexan-3-ones,thujone and isothujone

(lS,5S)-exo-2(R)-Methylbicyclo[3.1.0]hexan-3-one ($\text{1}$) and (lS,5S)-endo-2(S)-methylbicyclo[3.1.0]hexan-3-one (2) were synthesized and their circular dichroism (CD) spectra run. Conformational analysis based on molecular mechanics calculations and Karplus equation analyses of vicinal H¦H NMR coupling constants indicate boat-like sofa conformations for both $\text{1}$ and $\text{2}$, with very little ring distortion from the symmetry of the parent bicyclo[3.1.0]hexan-3-one. The lone dissymmetric ψ-axial and ψ-equatorial methyl groups of $\text{1}$ and $\text{2}$, respectively, are both octant consignate. The natural product analogs of $\text{1}$ and $\text{2}$, (?)-3-isothujone ($\text{3}$) and (+)-3-thujone ($\text{4}$) were prepared and examined similarly. Their α-methyl perturbers dominate the CD n-π^★ Cotton effects.     

Nuclear analogs of β-lactam antibiotics. 7. The synthesis of 3-thia- and 3-aza-1-dethiaceph-1-em esters

The total synthesis of a 3-thia- and a 3-aza-1-dethiacepham ($\text{9}$ and $\text{16}$) are described. Neither compound possessed antibacterial activity $\text{vs}$$\text{B}$. $\text{subtilis}$. An unsaturated analog, a 3-aza-1-dethiaceph-1-em exhibited weak antibacterial activity.     

1-phenyl-3-(trifluormethansulfonyl)-propadien

For the first time a perfluoroalkanesulfonylallene, the 1-phenyl-3-(trifluoromethanesulfonyl)-propadiene ($\text{5}$) was synthesized. $\text{5}$ is $\text{5}$ reacts already at room temperature with cyclopentadiene to form the adduct $\text{6}$.     

The chemistry of 2'' ,3''-seconucleosides II. Reactions and biological properties of 2'',3''-secopyrimidine ribonucleosides

Reaction of 2',3'-secouridine with acetone gave the 3',5'-$\text{O}$-isopropylidene derivative (1) which upon treatment with mesylchloride gave the 2'-$\text{O}$-mesyl compound (2). Replacement of the mesyl group of 2 with halide could be effected by reaction with a metal halide in DMF. The 3',5'-$\text{O}$-isopropylidene group was removed simultaneously to give a 2'-halogeno-2'-deoxy-2',3'-secouridine. 2',3'-Dichloro-2',3'-dideoxy-2',3'-secouridine upon treatment with base gave 6($\text{R}$)-chloromethyl-2($\text{R}$)-(uracil-1-yl)-1,4-dioxane in addition to O²,2'-anhydro-3'-chloro-3'-deoxy-2',3'-secouridine, as previously reported. 2',3'-Dichloro-2',3'-dideoxy-5'-0-trityl-2',3'-secouridine was converted to 2',3'-dichloro-2',3'-dideoxy-2',3'-secocytidine (16) $\text{via}$ a triazole derivative. Compound 16 was unstable and appeared to form O²,2'-anhydro-3'-chloro-3'-deoxy-2,3'-secocytidine upon standing at room temperature. 5-Vinyl- and 5-($\text{E}$) (2-bromovinyl) uridine dialdehydes have been made, as well as a number of other 5-substituted 2',3'-secouridine derivatives. None of the compounds obtained showed significant activity against a number of virus strains or tumor cell lines, except for 5-($\text{E}$)(2-bromovinyl) uridine dialdehyde, which was inhibitory to the growth of human lymphoblast (Raji, Namalva) cells at a concentration of 28 μ/ml.     

Palladium-catalyzed cyclization reactions of 3-propargylthio 1,2,4-triazin-5(2h)-ones to thiazolo-1,2,4-triazinones

Selective transformation of 3-propargylthio-1,2,4-triazin-5(2H)-ones ($\text{1}$) to 6-methylene-6,7-dihydro-4H-thiazolo[2,3-c][1,2,4]-triazin-4-ones ($\text{2}$) and 3-methylene-2,3-dihydro-7H-thiazolo[3,2-b]-[1,2,4]triazin-7-ones ($\text{3}$) is performed under the conditions of Pd(II) salt or sodium hydroxide catalysis, respectively.