New Lignan,Benzofuran, and Sesquiterpene Derivatives from the Roots of Leontopodium alpinum and L. leontopodioides

Three new compounds, including a benzofuran, 1‐{(2R*,3S*)‐3‐(β‐D ‐glucopyranosyloxy)‐2,3‐dihydro‐2‐[1‐(hydroxymethyl)vinyl]‐1‐benzofuran‐5‐yl}ethanone ( 1 ), a lignan, [(2S,3R,4R)‐4‐(3,4‐dimethoxybenzyl)‐2‐(3,4‐dimethoxyphenyl)tetrahydrofuran‐3‐yl]methyl (2E)‐2‐methylbut‐2‐enoate ( 2 ), and a silphiperfolene‐type sesquiterpene, [(1S,2Z,3aS,5aS,6R,8aR)‐1,3a,4,5,5a,6,7,8‐octahydro‐1,3a,6‐trimethylcyclopenta[c]pentalen‐2‐yl]methyl acetate ( 3 ), together with the known coumarins obliquin ( 4 ) and its 5‐methoxy derivative 5 were isolated from the roots of Leontopodium alpinum. Another known coumarin derivative, 5‐hydroxyobliquin ( 6 ), was isolated from the roots of L. leontopodioides. The structures of these compounds were established by spectroscopic studies.     

A new approach for the synthesis of some pyrazolo[5,1‐c]triazines and pyrazolo[1,5‐a]pyrimidines containing naphtofuran moiety

Naphtho[2,1‐b]furan‐2‐yl)(8‐phenylpyrazolo[5,1‐c][1,2,4]triazin‐3‐yl)methanone, ([1,2,4]triazolo[3,4‐c][1,2,4]triazin‐6‐yl)(naphtho[2,1‐b]furan‐2‐yl)methanone, benzo[4,5]imidazo[2,1‐c][1,2,4]triazin‐3‐yl‐naphtho[2,1‐b]furan‐2‐yl‐methanone, 5‐(naphtho[2,1‐b]furan‐2‐yl)pyrazolo[1,5‐a]pyrimidine, 7‐(naphtho[2,1‐b]furan‐2‐yl)‐[1,2,4]triazolo[4,3‐a]pyrimidine, 2‐naphtho[2,1‐b]furan‐2‐yl‐benzo[4,5]imidazo[1,2‐a]pyrimidine, pyridine, and pyrazole derivatives are synthesized from sodium salt of 5‐hydroxy‐1‐naphtho[2,1‐b]furan‐2‐ylpropenone and various reagents. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation, and alternative synthetic route whenever possible. J. Heterocyclic Chem., (2012).     

Studies on ketene and its derivatives. CXI . Photoreaction of diketene with 2(1H)-quinolone derivatives

Photoreaction of diketene with 4-methyl-2(1H)-quinolone and 1,4-dimethyl-2(1H)-quinolone gave 2R*,2aR*,SbR*- and 2R*,2aS*8bS*-8b-methyl-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]quinoline-2-spiro-2′-(oxetan)-4′-one ( 6a and 6b ), and their 4-methyl derivatives 7a and 7b , respectively. Thermolysis of compounds 6 and 7 afforded 2aR*,8bS*-8b-methyl-2-methylene-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]quinoline ( 8 ) and its 4-methyl derivatives 9 , respectively. Similarly, photolysis of diketene and 4-acetoxy-2(1H)-quinolone gave 1R*,2aS*,8bS*- and 1R*,2aR*,8bR*-8b-acetoxy-3-oxo-1,2,2a,3,4,8b-hexahydrocyclobuta[c]-quinoline ( 11a and 11b ). Alcoholysis of compounds 11a and 11b with hydrogen chloride in methanol gave 1-hydroxy-1-(methoxycarbonyl)methylcyclobuta[c]quinoline derivative 12 and 13 which were transformed to 4-acetyl-3-methyl-2(1H)-quinolone ( 15 ) by further alcoholysis. Photoreaction of diketene with 2(1H)-quinolone derivatives gave the corresponding cyclobuta[c]quinoline spirooxetanone derivatives 18 and 23 , which, by thermolysis, were transformed to 2-methylenecyclobuta[c]quinoline 23 and 25 , respectively.     

Two New Sesquiterpenes from the Roots of Valeriana fauriei Briq.

A phytochemical investigation of the MeOH extract of Valeriana fauriei Briq . roots resulted in the isolation of two new sesquiterpenes, isovalerianin A (=(1β,4Z,6β,8α)‐8‐(acetyloxy)‐1,10‐dihydroxy‐6,11‐cyclogermacr‐4‐en‐15‐al=rel‐(1R,2Z,6S,7R,9R,10S)‐9‐(acetyloxy)‐6,7‐dihydroxy‐7,11,11‐trimethylbicyclo[8.1.0]undec‐2‐ene‐3‐carboxaldehyde; 1 ) and valerianin C (=(2α,3α,6α,8α)‐3‐(acetyloxy)‐2,4,8‐trihydroxyguai‐1(10)‐ene‐12,6‐lactone=rel‐(3R,3aS,4R,7S,8S,9R,9aR,9bR)‐8‐(acetyloxy)‐3a,4,5,7,8,9,9a,9b‐ octahydro‐4,7,9‐trihydroxy‐3,6,9‐trimethylazuleno[4,5‐b]furan‐2(3H)‐one; 2 ), together with six known compounds, i.e., camphor, methyl 4‐hydroxybenzoate, 2‐methoxybenzoic acid, benzoic acid, quercetin, and kaempferol. The structures of the compounds were established by detailed spectral analysis and comparison with previously reported data.     

Synthesis of Heteroanellated Pyranosides Starting from Methyl 4,6‐O‐benzylidene‐2,3‐dideoxy‐α‐d‐erythro‐hexopyranosid‐2‐ylidenemalononitrile

The hexopyranosid‐2‐ylidenemalononitrile 1 reacted with phenyl isothiocyanate in the presence of triethylamine to furnish (2R,4aR,6S,10bS)‐8‐amino‐4a,6,10,10b‐tetrahydro‐6‐methoxy‐2‐phenyl‐10‐phenylimino‐4H‐thiopyrano[3′,4′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (2). Starting from 1, cyclization with sulphur and diethylamine yielded (2R,4aR,6S,9bR)‐8‐amino‐4,4a,6,9b‐tetrahydro‐6‐methoxy‐2‐phenylthieno[2′,3′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (3), which could be transformed into the corresponding aminomethylenamino derivative 4 by treatment with triethyl orthoformate and ammonia. Intramolecular cyclization of 4 to yield (2R,4aR,6S,11bR)‐4,4a,6,11b‐tetrahydro‐6‐methoxy‐2‐phenyl[1,3]dioxino[4″,5″:5′,6′]pyrano[3′,4′:4,5]thieno [2,3‐d]pyrimidin‐7‐amine (5) was achieved by using NaH as base. (2R,4aR,6S,9bS)‐8‐Amino‐4a,6,9,9b‐tetrahydro‐6‐methoxy‐9‐(4‐methylphenyl‐sulfonyl)‐2‐phenyl‐4H‐[1,3]dioxino[4′,5′:5,6]pyrano[4,3‐b]pyrrole‐7‐carbonitrile (6) was prepared by treatment of compound 1 with tosylazide and triethylamine.     

Asymmetric Syntheses of New Polyhydroxylated Quinolizidines: Cross‐Aldol Reactions of 7‐Oxabicyclo[2.2.1]heptan‐2‐one and 3a,4a,7a,7b‐Tetrahydro[1,3]dioxolo[4,5]furo[2,3‐d]isoxazole‐3‐carbaldehyde Derivatives

The cross‐aldolization of (−)‐(1S,4R,5R,6R)‐6‐endo‐chloro‐5‐exo‐(phenylseleno)‐7‐oxabicyclo[2.2.1]heptan‐2‐one ((−)‐ 25 ) and of (+)‐(3aR,4aR,7aR,7bS)‐ ((+)‐ 26 ) and (−)‐(3aS,4aS,7aS,7bR)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]furo[2,3‐d]isoxazole‐3‐carbaldehyde ((−)‐ 26 ) was studied for the lithium enolate of (−)‐ 25 and for its trimethylsilyl ether (−)‐ 31 under Mukaiyama's conditions (Scheme 2). Protocols were found for highly diastereoselective condensation giving the four possible aldols (+)‐ 27 (`anti'), (+)‐ 28 (`syn'), 29 (`anti'), and (−)‐ 30 (`syn') resulting from the exclusive exo‐face reaction of the bicyclic lithium enolate of (−)‐ 25 and bicyclic silyl ether (−)‐ 31 . Steric factors can explain the selectivities observed. Aldols (+)‐ 27 , (+)‐ 28 , 29 , and (−)‐ 30 were converted stereoselectively to (+)‐1,4‐anhydro‐3‐{(S)‐[(tert‐butyl)dimethylsilyloxy][(3aR,4aR,7aR,7bS)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]‐furo[2,3‐d]isoxazol‐3‐yl]methyl}‐3‐deoxy‐2,6‐di‐O‐(methoxymethyl)‐α‐D ‐galactopyranose ((+)‐ 62 ), its epimer at the exocyclic position (+)‐ 70 , (−)‐1,4‐anhydro‐3‐{(S)‐[(tert‐butyl)dimethylsilyloxy][(3aS,4aS,7aS,7bR)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]furo[2,3‐d]isoxazol‐3‐yl]methyl}‐3‐deoxy‐2,6‐di‐O‐(methoxymethyl)‐α‐D ‐galactopyranose ((−)‐ 77 ), and its epimer at the exocyclic position (+)‐ 84 , respectively (Schemes 3 and 5). Compounds (+)‐ 62 , (−)‐ 77 , and (+)‐ 84 were transformed to (1R,2R,3S,7R,8S,9S,9aS)‐1,3,4,6,7,8,9,9a‐octahydro‐8‐[(1R,2R)‐1,2,3‐trihydroxypropyl]‐2H‐quinolizine‐1,2,3,7,9‐pentol ( 21 ), its (1S,2S,3R,7R,8S,9S,9aR) stereoisomer (−)‐ 22 , and to its (1S,2S,3R,7R,8S,9R,9aR) stereoisomer (+)‐ 23 , respectively (Schemes 6 and 7). The polyhydroxylated quinolizidines (−)‐ 22 and (+)‐ 23 adopt `trans‐azadecalin' structures with chair/chair conformations in which H−C(9a) occupies an axial position anti‐periplanar to the amine lone electron pair. Quinolizidines 21 , (−)‐ 22 , and (+)‐ 23 were tested for their inhibitory activities toward 25 commercially available glycohydrolases. Compound 21 is a weak inhibitor of β‐galactosidase from jack bean, of amyloglucosidase from Aspergillus niger, and of β‐glucosidase from Caldocellum saccharolyticum. Stereoisomers (−)‐ 22 and (+)‐ 23 are weak but more selective inhibitors of β‐galactosidase from jack bean.     

A Novel Dimeric Podophyllotoxin‐Type Lignan and a New Withanolide from Withania coagulans

A novel dimeric lignan, bispicropodophyllin glucoside ( 1 ) and a highly oxygenated new withanolide, coagulin S ( 2 ) were isolated from the ethanolic extract of Withania coagulans. The structures were established on the basis of the spectroscopic data and have been identified as (5S*,5aR*,8aR*,9S*,15S*,15aS*,18aS*,19S*)‐9,19‐di‐β‐D ‐glucopyranosyl‐5,8a,9,15,15a,18,18a,19‐octahydro‐5,15‐bis(3,4,5‐trimethoxyphenyl)bis([1,3]dioxolo[4′,5′:6,7]naphtho)[2,3‐c:2,3‐h][1,6]dioxecin‐6,16(5aH,8H)‐dione ( 1 ) and (20S*,22R*)‐5α,6β,14α,15α,17β,20,27‐heptahydroxy‐1‐oxowith‐24‐enolide ( 2 ), respectively.     

Novel Convenient Synthesis of Mitiglinide

A novel convenient synthesis of the hypoglycemic agent mitiglinide was developed. (2S)‐4‐[(3aR,7aS)‐Octahydro‐2H‐isoindol‐2‐yl]‐4‐oxo‐2‐benzyl‐butanoic acid (6) was prepared by selective hydrolysis of ethyl 4‐[(3aR,7aS)‐octahydro‐2H‐isoindol‐2‐yl]‐4‐oxo‐2‐benzyl‐butanoate (5) using α‐chymotrypsin; the latter was prepared by a novel facile route from (3aR,7aS)‐octahydro‐2H‐isoindole. The overall yield was 25.6%.     

Precursors to dodecahedrane

The title compounds, (2R,2′′S,3b′S,4a′R,7b′S,8a′R)‐per­hydro­di­spiro­[furan‐2,3′‐di­cyclo­penta­[a,e]­pentalene‐7′,2′′‐furan]‐5,5′′‐dione, C₂₀H₂₆O₄, and (3aR,3bR,4aR,4bS,5aS,8aR,8bR,9aR,9bS,10aS)‐per­hydro­dipentaleno­[2,1‐a:2′,1′‐e]­pentalene‐1,6‐dione, C₂₀H₂₆O₂, are intermediates identified during the synthesis of dodecahedrane. Crystallographic studies have established the ring‐junction stereochemistry for these important intermediates. All the ring junctions are cis‐fused, and the molecular packing is stabilized by van der Waals interactions.     

Packing in three cyclooctitol acetates

Three cyclooctitol derivatives, in the form of a tetraacetate, (1S*,2R*,3S*,4S*)‐2,3,4‐triacetoxycyclooctan‐1‐ylmethyl acetate, C₁₇H₂₆O₈, and two regioisomeric acetonide triacetates, (3aS*,4R*,8S*,9S*,9aS*)‐8,9‐diacetoxy‐2,2‐dimethylcyclooctano[d][1,3]dioxan‐4‐ymethyl acetate and (3aS,4R,7S,9R,9aS)‐7,9‐diacetoxy‐2,2‐dimethylcyclooctano[d][1,3]dioxan‐4‐ylmethyl acetate, both C₁₈H₂₈O₈, have been studied. The conformation of the cyclooctane ring in the three compounds is quite close to the boat–chair form of the parent hydrocarbon. Packing is effected through weak C—H...O and van der Waals contacts.     

Furopyridines. XVIII. Photocycloaddition of furo[2,3-c]pyridin-7(6H)-one with acrylonitrile

The photocycloaddition of furo[2,3-c]pyridin-7(6H)-one ( 1 ) and its N-mefhyl derivative ( 1-Me ) to acrylonitrile has been studied. The structures of the photoadducts isolated by colum chromatography were determined by the nuclear magnetic resonance spectroscopy and single crystal X-ray analysis. The cyclo-addition of 1 afforded an adduct 2 at the carbonyl oxygen and 8-cyano-8,9-dihydrofuro[d]azocin-7(6H)-one ( 3 ), and the addition of 1-Me the N-methyl derivative 3-Me of 3 , (9S*)-9-cyano-6-methyl-3a,7a-dihydro-3a,7a-ethanofuro[2,3-c]pyridin-7(6H)-one ( 4 ), (2S*, 2aR*, 7bR*)- ( 5 ) and (1R*, 2aS*, 7bS*)-2-cyano-3-methyl-4-oxo-1,2,2a,3,4,7b-hexahydrocyclobuta[e]furo[2,3-c]pyridine ( 6 ).     

New Monoterpene-Substituted Dihydrochalcones from Piper aduncum

Five New unusual monoterpene-substituted dihydrochalcones, the adunctins A–E (1″S)-1-{2′-hydroxy-4′-methoxy-6′-[4″-methyl-1″-(1?-methylethyl)cyclohex-3″ -en-1″ -yloxy]phenyl}-3-phenylpropan-1-one ( 1 ), (5aR*,8R*,9aR*)-3-phenyl-1-[5′,8′,9′,9′a-tetrahydro-3′-hydroxy-1′-methoxy-8′-(1″-methylethyl)-5′-a-methyldibenzo-[b,d]furan-4′-yl]propan-1-one ( 2 ), (2′R*,4″S*)-1-{6′-hydroxy-4′-methoxy-4″-(1?-methylethyl)spiro[benzo[b]-furan-2′(3′H),1″ -cyclohex-2″ -en]-7′-yl}-3-phenylpropan-1-one ( 3 ), (2′R*,4″R*)-1-{6′-hydroxy-4′-methylethyl-4″-(1?-methylethyl)spiro[benzo[b]furan-2′(3′H),1″-cyclohex-2″-en]-7′-yl}-3-phenypropan-1-one ( 4 ), and (5′aR*,6′S*, 9′R*,9′aS*)-1-[5′a,6′,7′,8′,9′a-hexahydro-3′,6′-methoxy-6′-methyl-9′-(1″-methylethyl)dibenzo[b,d]-furan-4′-yl]-3-phenylpropan-1-one ( 5 ) were isolated from the leaves of Piper aduncum (Piperaceae) by preparative liquid chromatography. In addition, (?)-methyllindaretin ( 6 ), trans-phytol, and α-tocopherol ( = vitamin E) were also isolated and identified. The structures were elucidated by spectroscopic methods, including 1D- and 2D-NMR spectroscopy as well as single-crystal X-ray diffraction analysis. The antibacterial and cytotoxic potentials of the isolates were also investigated.     

Absolute structures and conformations of the spongian diterpenes spongia‐13(16),14‐dien‐3‐one,epispongiadiol and spongiadiol

The absolute configurations of spongia‐13(16),14‐dien‐3‐one [systematic name: (3bR,5aR,9aR,9bR)‐3b,6,6,9a‐tetramethyl‐4,5,5a,6,8,9,9a,9b,10,11‐decahydrophenanthro[1,2‐c]furan‐7(3bH)‐one], C₂₀H₂₈O₂, (I), epispongiadiol [systematic name: (3bR,5aR,6S,7R,9aR,9bR)‐7‐hydroxy‐6‐hydroxymethyl‐3b,6,9a‐trimethyl‐3b,5,5a,6,7,9,9a,9b,10,11‐decahydrophenanthro[1,2‐c]furan‐8(4H)‐one], C₂₀H₂₈O₄, (II), and spongiadiol [systematic name: (3bR,5aR,6S,7S,9aR,9bR)‐7‐hydroxy‐6‐hydroxymethyl‐3b,6,9a‐trimethyl‐3b,5,5a,6,7,9,9a,9b,10,11‐decahydrophenanthro[1,2‐c]furan‐8(4H)‐one], C₂₀H₂₈O₄, (III), were assigned by analysis of anomalous dispersion data collected at 130 K with Cu Kα radiation. Compounds (II) and (III) are epimers. The equatorial 3‐hydroxyl group on the cyclohexanone ring (A) of (II) is syn with respect to the 4‐hydroxymethyl group, leading to a chair conformation. In contrast, isomer (III), where the 3‐hydroxyl group is anti to the 4‐hydroxymethyl group, is conformationally disordered between a major chair conformer where the OH group is axial and a minor boat conformer where it is equatorial. In compound (I), a carbonyl group is present at position 3 and ring A adopts a distorted‐boat conformation.     

Three ginkgolide hydrates from Ginkgo biloba L.: ginkgolide A monohydrate,ginkgolide C sesquihydrate and ginkgolide J dihydrate,all determined at 120 K

A low‐temperature structure of ginkgolide A monohydrate, (1R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐dimethylethyl)‐hexa­hydro‐4,7b‐di­hydroxy‐8‐methyl‐9H‐1,7a‐epoxymethano‐1H,6aH‐cyclo­penta­[c]­furo­[2,3‐b]­furo­[3′,2′:3,4]­cyclopenta­[1,2‐d]­furan‐5,9,12(4H)‐trione monohydrate, C₂₀H₂₄O₉·H₂O, obtained from Mo Kα data, is a factor of three more precise than the previous room‐temperature determination. A refinement of the ginkgolide A monohydrate structure with Cu Kα data has allowed the assignment of the absolute configuration of the series of compounds. Ginkgolide C sesquihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11S,11aR)‐3‐(1,1‐di­methyl­ethyl)‐hexa­hydro‐2,4,7b,11‐tetrahydroxy‐8‐methyl‐9H‐1,7a‐epoxy­methano‐1H,6aH‐cyclopenta­[c]­furo­[2,3‐b]­furo­[3′,2′:3,4]­cyclo­penta­[1,2‐d]­furan‐5,9,12(4H)‐trione sesquihydrate, C₂₀H₂₄O₁₁·1.5H₂O, has two independent diterpene mol­ecules, both of which exhibit intramolecular hydrogen bonding between OH groups. Ginkgolide J dihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐di­methyl­ethyl)‐hexa­hydro‐2,4,7b‐tri­hydroxy‐8‐methyl‐9H‐1,7a‐epoxy­methano‐1H,6aH‐cyclo­penta­[c]­furo­[2,3‐b]furo[3′,2′:3,4]­cyclo­penta­[1,2‐d]­furan‐5,9,12(4H)‐trione dihydrate, C₂₀H₂₄O₁₀·2H₂O, has the same basic skeleton as the other ginkgolides, with its three OH groups having the same configurations as those in ginkgolide C. The conformations of the six five‐membered rings are quite similar across ­ginkgolides A–C and J, except for the A and F rings of ginkgolide A.     

New aspects of reactions of methyl (thio)ureas with benzil

New pathways of reaction between 1-methylthiourea or 1-methylurea and benzil bring about new derivatives of (2S*,3aR*,6aS*)-perhydro-3aH-[1,3]dioxolo[4,5-d]imidazole and racemic (4S*,5R*)-4-alkoxy-5-hydroxy-1-methyl-4,5-diphenylimidazolidine-2-thiones. Some of the obtained urea-and thiourea derivatives were characterized by X-ray diffraction, which showed their supramolecular organization governed by the directionality of hydrogen bonds at the acceptor side C=O or C=S groups.     

Bisabolane Derivatives from Leontopodium alpinum

From the roots of Leontopodium alpinum, four new bisabolane sesquiterpenoids, (1R*,2S*,4R*,5S*)‐4‐(acetyloxy)‐2‐[3‐(acetyloxy)‐1,5‐dimethylhex‐4‐enyl]‐5‐methylcyclohexyl (2Z)‐2‐methylbut‐2‐enoate ( 1 ), (1R*,4S*,6R*)‐4‐(acetyloxy)‐6‐[3‐(acetyloxy)‐1,5‐dimethylhex‐4‐enyl]‐3‐methylcyclohex‐2‐en‐1‐yl (2Z)‐2‐methylbut‐2‐enoate ( 2 ), and 3‐methyl‐1‐{2‐[(1R*,2R*,5R*,6S*)‐2,5,6‐tris(acetyloxy)‐4‐methylcyclohex‐3‐en‐1‐yl]propyl}but‐2‐enyl (2Z)‐2‐methylbut‐2‐enoate ( 3 and 4 ) have been isolated. The latter constituents differ from each other by the relative configurations of the chiral centers of the hexenyl side chain.     

Reactions of N- and C-alkenylanilines: IX. Synthesis, oxidation, and nitration of some 7-methyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles

Heating of 4-acyl-3-iodo-7-methyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indoles in piperidine gave 4-acyl-7-methyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles which were oxidized with KMnO4 to obtain the corresponding 4-acyl-7-methyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indole-1,2-diols. Oxidation of 4-acyl-7-methyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles at the olefinic double bond with hydrogen peroxide in acetonitrile in the presence of formic acid afforded stereoisomeric epoxides with cis and trans orientation of the nitrogen-containing and oxirane rings. Nitration with a mixture of ammonium nitrate and trifluoroacetic anhydride produced 5-nitro derivatives. The structure of 1-{(1aR*,1bR*,6bS*,7aS*)-5-methyl-1a,1b,2,6b,7,7ahexahydrooxireno[4,5]cyclopenta[1,2-b]indol-2-yl}ethanone was determined by X-ray analysis.     

Reaction of 2‐acyl‐6‐methylbenzo[b]furan‐3‐acetic acids derivatives with hydrazine

Reaction of 2‐acyl‐6‐methylbenzo[b]furan‐3‐acetic acids and their derivatives such as amides and esters with hydrazine does not give expected 1‐alkyl‐5H‐benzofuro[2,3‐e]diazepin‐4‐ones ones but results in 2‐amino‐7‐methyl‐2H‐benzo[4,5]furo[2,3‐c]pyridin‐3‐ones or (3‐R‐6‐methylbenzo[b]furan‐2‐yl)alkyl ketone azines.     

Terpenoids from the Roots of Ligularia muliensis

Three new eremophilane‐type sesquiterpenes, (6β,8α)‐6‐(acetyloxy)‐8‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 1 ), (6α,8α)‐6‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 2 ), and (6α,8α)‐6‐(acetyloxy)eremophil‐7(11)‐en‐12,8‐olide ( 3 ) ((8α)‐eremophil‐7(11)‐en‐12,8‐olide = (4aR,5S,8aR,9aS)‐4a,5,6,7,8,8a,9,9a‐octahydro‐3,4a,5‐trimethylnaphtho[2,3‐b]furan‐2(4H)‐one), besides the recently elucidated eremoligularin ( 4 ) and bieremoligularolide ( 5 ), as well as a new highly oxygenated monoterpene, rel‐(1R,2R,3R,4S,5S)‐p‐menthane‐1,2,3,5‐tetrol ( 12 ), together with six known constituents, i.e., the sesquiterpenes 6 and 7 , the norsesquiterpenes 8 – 10 , and the monoterpene 13 , were isolated from the roots of Ligularia muliensis. In addition, an attempt to dimerize 1 to a bieremophilenolide (Scheme) resulted in the generation of the new derivative (6β,8β)‐6‐(acetyloxy)‐8‐chloroeremophil‐7(11)‐en‐12,8‐olide ( 11 ). The new structures were established by means of detailed spectroscopic analysis (IR, FAB‐, EI‐, or HR‐ESI‐MS as well as 1D‐ and 2D‐NMR experiments). Compounds 4 and 5 were evaluated for their antitumor effects in vitro (Table 3).     

New Sesquiterpenoids from Lycianthes marlipoensis

Two new sesquiterpenoids and one derivative, lycifuranone A (= (4R)‐4,5‐dihydro‐4‐(3‐hydroxy‐2,6‐dimethylbenzyl)‐5,5‐dimethylfuran‐2(3H)‐one; 1 ), lycifuranone B (= 4,5‐dihydroxy‐3‐methyl‐2‐{[(3R)‐tetrahydro‐2,2‐dimethyl‐5‐oxofuran‐3‐yl]methyl} benzaldehyde; 2 ), and lycifuranone C (= (4R)‐4‐(3,4‐dihydroxy‐6‐{(2S,4R,6S)‐4‐[2‐(4‐hydroxy‐3‐methoxyphenyl)ethyl]‐6‐pentyl[1,3]dioxan‐2‐yl}‐2‐methylbenzyl)‐4,5‐dihydro‐5,5‐dimethylfuran‐2(3H)‐one; 3 ), respectively, have been isolated from the roots of Lycianthes marlipoensis, and their structures were established by spectroscopic methods.