A reinvestigation of the structures of acomonine,iliensine, 14-dehydroiliensine,and 14-benzoyliliensine

The novel structures assigned by Yunusov et al to the C₁₉-diterpenoid alkaloids, acomonine ($\text{1}$), iliensine ($\text{2}$), 14-dehydroiliensine ($\text{3}$), and 14-bensoyliliensine ($\text{4}$) have been found to be in error. We have demonstrated that these alkaloids are identical with the well-known alkaloids, delsoline ($\text{5}$), delcosine ($\text{6}$), 14-dehydrodeloosine ($\text{7}$), and 14-benzoyldelcosine ($\text{8}$), respectively.     

Synthesis,structure, and reactions of thiocarbonic acid derivatives new pentathiodipercarbonates, (RSS)2 CS, α,α,α-tris(disulfides), and the first α,α,α-tris(trisulfide)

Novel bis(perhaloalkyl) pentathiodipercarbonates $\text{5b-d}$ have been synthesized by reaction of sulfenyl chlorides with metal trithiocarbonates, and the heptathio analog $\text{21a}$ was prepared similarly. Lenthionine $\text{19}$ is the main product when diiodomethane is treated with sodium tetrathiopercarbonate. A rearrangement of bis(alkyldithio)chloromethanesulfenyl chlorides $\text{22}$ to alkyldithio) (alkyltrithio)dichloromethanes $\text{24}$ has been observed. Additions of sulfenyl chlorides and of thiosulfenyl chlorides to the thiocarbonyl compounds $\text{5}$ and $\text{21a}$ were achieved in acetonitrile. The structures of the first crystalline pentathiodipercarbonate $\text{5a}$ and α,α,α-tris(disulfide) $\text{29a}$, and of the first reported α,α,α-tris(trisulfide)$\text{31a}$ have been determined by X-ray crystallography.     

Stereoselective syntheses of substituted methyl (Z,E,E)-deca-2,7.9-trienoates and substituted methyl (Z,E,E)-undeca-2,8,10-trienoates

Lindlar hydrogenation of substituted methyl ($\text{E}$,$\text{E}$)-deca-7,9-dien-2-ynoates and substituted methyl ($\text{E}$,$\text{E}$)-undeca-8,10-dien-2-ynoates affords selectively the corresponding ($\text{Z}$,$\text{E}$,$\text{E}$)-trienes.     

New Phenyl propanoids having weak piscicidal action and the related compound: wutaiensol,wutaiensal, wutaialdehyde,and methyl demethoxywutaiensate

The structures of three new prenylphenyl propanoids, wutaiensol ($\text{1}$), wutaiensal ($\text{2}$), and methyl demethoxywutaiensate ($\text{4}$) were established by correlating with S-rutaretin methyl ether ($\text{9}$) or S-marmesin ($\text{24}$) by chemical means. The structure of wutaialdehyde ($\text{3}$), a related compound, was also established by total synthesis of the racemate and by correlating with $\text{1}$. Preliminary piscicidal test on these compounds disclosed that $\text{2}$ and $\text{4}$ are weakly bu distinctly positive.     

Structure de la gouregine,alcaloïde orginal apparente aux cularines

The structure of guoregine, a new isoquinoline alkaloid from $\text{G}$$\text{u}$$\text{a}$$\text{t}$$\text{t}$$\text{e}$$\text{r}$$\text{i}$$\text{a}$$\text{o}$$\text{u}$$\text{r}$$\text{e}$$\text{g}$$\text{o}$$\text{u}$, Annonaceae, has been deduced by spectral analysis and confirmed by an X-ray structure determination. It is the first member of a new class of cularine-related alkaloids (α-$\text{g}$$\text{e}$$\text{m}$-dimetyltetradehydrocularines).     

Five new steroidal glycosides,pregnedioside-A, -B,and their three monoacetates,from an Okinawan soft coral of Alcyonium sp.

Five new pregnene-type steroidal glycosides, named pregnedioside -a ($\text{1}$), 4′-O-acetyl-pregnedioside-a ($\text{2}$), 3′-O-acetyl-pregnedioside-a ($\text{3}$), pregnedioside-b ($\text{5}$), and 4′-O-acetyl-pregnedioside-b ($\text{6}$), were isolated from an Okinawan soft coral of Alcyonium sp. and their structures were elucidated. These are rare examples of steroidal gylcosides from soft coral.     

Kalashine,a novel type aporphine-benzylisoquinoline alkaloid

$\text{Berberis orthobotrys}$ produces the new dimer kalashine ($\text{1}$), together with the previously reported pakistanamine ($\text{2}$) and pakistanine ($\text{3}$). Kalashine is the first aporphine-benzylisoquinoline known to be substituted at C-11. Acid catalyzed rearrangement of pakistanamine ($\text{2}$) in 3N HCl leads to 1-0-methylpakistanine ($\text{6}$) together with small amounts of 1-0-methylkalashine ($\text{7}$) and (+)-armepavine ($\text{8}$). Rearrangement of $\text{2}$ using methanol containing a little 3N HCl gives about equal amounts of $\text{6}$ and 1,10-di-O-methylpakistanine ($\text{9}$).     

Synthesis of (2S,3R,1'R)-stegobinone,the pheromone of the drugstore beetle,with stereocontrol at C-2 and C-1'

(2$\text{S}$,3$\text{R}$,1'$\text{R}$)-Stegobinone [2,3-dihydro-2,3,5-trimethyl-6-(1'-methyl-2'-oxobutyl)-4H-pyran-4-one], the pheromone of $\text{Stegobium}$ $\text{paniceum}$ L., was synthesized with stereocontrol at C-2 and C-1' starting from ethyl ($\text{R}$)-3-hydroxybutanoate and methyl ($\text{R}$)-3-hydroxy-2-methylpropanoate. The dihydro-γ-pyrone ring of the pheromone was constructed by an intramolecular acylation followed by acid-catalyzed cyclization.     

Trimethymetall-urotropinaddukte des aluminiums,galliums, indiums und thalliums

Reactions of urotropine (C₆H₁₂N₄) with trimethylmetal derivatives of Al, Ga, In und Tl in various ($\text{1}\text{1}$$\text{1}\text{4}$) molar ratios lead to stable and monomeric $\text{1}\text{1}$, $\text{1}\text{2}$ or $\text{1}\text{3}$ adducts in good yields, but no $\text{1}\text{4}$ addition product could be isolated. The vibrational spectra (IR and Raman) of all compounds are recorded and partly assigned. Some characteristic frequencies of the C₆N₄-skeletons clearly show the symmetry changes in the series of the $\text{1}\text{1}$ → $\text{1}\text{2}$ → $\text{1}\text{3}$ adducts (C_3ν → C_2ν → C_3ν). The X-ray structure determinations of C₆H₁₂N₄·.GaMe₃ (MeCH₃) and C₆H₁₂N₄·.2GaMe₃, are in good agreement with the vibrational spectra. Both compounds crystallize in monoclinic space groups (P2₁ and C2/c). The GaN distances are around 214 pm, and the values for the C₆N₄-skeletons are not significantly different from those for free urotropine.     

Short,stereocontrolled syntheses of irreversible eicosanoid biosynthesis inhibitors. 5,6- , 8,9- , and 11,12-dehydroarachidonic acid

5,6- and 11,12-dehydroarachidonic acids ($\text{1}$ and $\text{3}$), which $\text{irreversibly}$ inhibit leukotriene and prostaglandin biosynthesis, respectively, have been synthesized, along with the 8,9-isomer ($\text{2}$), by novel and direct routes.     

A convenient synthesis of flindersine,atanine and their analogues

A new synthesis of the pyranoquinolone alkaloids flindersine ($\text{8a}$), 8-methoxyflindersine ($\text{8c}$), N-methylflindersine ($\text{9a}$), zanthobunglanine ($\text{9c}$) oricine ($\text{9d}$) and veprisine ($\text{9e}$) and the prenylquinolone alkaloids atanine ($\text{13a}$), preskimmianine ($\text{13e}$) N-methylatanine ($\text{14a}$), O-methylglycosolone ($\text{14c}$) and N-methylpreskimmianine ($\text{14e}$) is described.     

Synthesis of erythrinin A,a naturally occurring pyranoisoflavone

Erythrinin A ($\text{10}$) has been synthesised by the oxidative rearrangement of dihydropyranochalcone $\text{1}$ with thallium(III) nitrate (TTN) in trimethyl orthoformate (TMOF) to the dimethyl acetal $\text{2}$, followed by cyclisation to $\text{3}$, demethylation to $\text{6}$ and dehydrogenation. Compound $\text{10}$ could also be obtained from chalcone $\text{4}$ on similar rearrangement followed by cyclisation, demethoxymethylation and dehydrogenation. In another route, chalcone $\text{7}$ was oxidatively rearranged with TTN in TMOF, to $\text{8}$ which on treatment with HCl yielded $\text{10}$.     

The reaction of trialkylstannylmethyllithium with α,β-epoxy ketones. A preparative method of β, γ-unsaturated ketones by homologation of α, gb-unsaturated ketones

α, β-epoxy ketones $\text{2}$, upon treatment with two equivalents of trialkylstannylmethyllithium $\text{1}$, afforded cyclopropanols $\text{3}$ as a single product in acyclic system, and a mixture of cyclopropanols $\text{3}$ and methylene 1,2-diols $\text{4}$ in cyclic system. Under acidic conditions, the cyclopropanols gave β, γ-unsaturated ketones $\text{5}$ in good yields.     

Photochemical valence tautomerization of berberinephenolbetaines to 8,14-cycloberbines,versatile aziridine derivatives for spirobenzylisoquinolines

Irradiation of the berberinephenolbetaines ($\text{8}$$\text{a}$, $\text{8}$$\text{b}$, and $\text{8}$$\text{c}$) effected valence tautomerization to give the 8,14-cycloberbines ($\text{9}$$\text{a}$, $\text{9}$$\text{b}$, and $\text{9}$$\text{c}$), the aziridine derivatives, in high yield. The 8,14-cycloberbines were efficiently converted to the spirobenzylisoquinolines by regioselective C bond cleavage.     

Conformational behaviour and inclusion compound forming properties of 5,18-disubstituted derivatives of 5, 11, 12, 18-tetrahydrotribenzo[b,f,j][1,4]diazacyclododecine-6, 17-dione

An X-ray structure analysis shows that the 5, 18-dimethyl derivative ($\text{5}$) of the title compound ($\text{4}$) crystallises from xylene as a 1:1 inclusion compound in which the host molecules adopt propeller-like conformations ($\text{7}$ and $\text{7}$*) with almost perfect $\text{C}$₂ symmetry. Dynamic ¹H n.m.r. spectroscopy shows that the 5, 18-dibenzyl derivative ($\text{6}$) of ($\text{4}$) forms a 1:1 inclusion compound with ethanol in the solid state and undergoes ring inversion ($\text{7}$ ? $\text{7}$*) between enantiomeric propeller-like conformations in solution against a barrier of 21.1 kcal mol^?1     

Synthesis and conformational behaviour of 1,9,17-triaza[2.2.2]metacyclophane-2, 10, 18-trione derivatives

The 1,9,17-triaza[2.2.2]metacyclophane-2, 10, 18-trione derivatives ($\text{1}$) – ($\text{3}$) have been synthesised. X-Ray crystallography shows that the 1,9,17-trimethyl derivative ($\text{3}$) adopts a Crown conformation ($\text{11}$) in the solid state. Dynamic n.m.r. spectroscopy indicates that both the 1,9-dimethyl-17-benzyl- ($\text{2}$) and 1,9,17-trimethyl- ($\text{3}$) derivatives exist as interconverting mixtures of Crown ($\text{11}$) and Saddle ($\text{12}$) conformations with the former predominating at equilibrium in solution.     

Acetylsanadaol,a diterpene having a novel skeleton,from the brown alga, Pachydictyon Coriaceum

Structures of new diterpenoids, sanadol ($\text{4}$) and acetylsanadol ($\text{5}$), isolated from $\text{Pachydictyon}$$\text{coriaceum}$, are determined, and sanadaol is produced by an acid-catalyzed ene reaction of dictyodial.     

Revised structure for fumarofine,an indenobenzazepine type alkaloid

Fumarofine is not a spirobenzylisoquinoline. Rather, it is the first know reduced indenobensazepine alkaloid, and possesses the cis B/C fused structure $\text{7}$. Rearrangement of synthetic spirobensylisoquinoline $\text{12}$ using methanesulfonyl chloride furnished indenobensazepine $\text{14}$. Osmium tetroxide oxidation of $\text{14}$ gave cis-glysol $\text{15}$. O-Methylfumarofine ($\text{8}$) was then obtained through pyridinium chlorochromate oxidation of $\text{15}$.     

Paeonilactone-A, -B,and -C,new monoterpenoids from paeony root

Three new monoterpenoids named paeonilactone-A, -B, and -C were isolated from Paeony root (roots of Paeonia albiflora PALLAS var. trichocarpa BUNGE) and their structures were determined to be $\text{2}$, $\text{3}$, and $\text{4}$, respectively, by means of chemical and spectroscopic studies.