2-甲基-6-(3-甲基-2-丁烯基)对苯二醌的合成

以邻甲基苯酚为原料,与1-氯-2-甲基-2-丁烯反应生成2-甲基-6-(3-甲基-2-丁烯基)苯酚,然后催化氧化得到目标产物2-甲基-6-(3-甲基-2-丁烯基)对苯二醌。该合成路线简单,易于操作,最终收率51%。     

Reactions of N- and C-Alkenylanilines: III. Synthesis and Cyclization of Substituted 2-(1-Methyl-2-butenyl)anilines

Reactions of substituted 2-(1-methyl-2-butenyl)anilines with iodine result in cyclization and formation of 3-iodo-1,2,3,4-tetrahydroquinolines; N-methylsulfonyl-2-(1-methyl-2-butenyl)anilines give rise exclusively to the corresponding 2-(1-iodoethyl)-3-methyl-2,3-dihydroindoles.     

Anti-isohumulone and its derivatives

Three new humulone derivatives have been isolated and identified as: 3,4-dihydroxy-2-(3-methyl-2-butenyl)-4-(4-methyl-3-pentenoyl)-2-cyclopentenone (6);4-ethanoyl-3,4-dihydroxy-2-(3-methyl-2-butenyl)-2-cyclopentenone (7) and 3,4-dihydroxy-2-(3-methyl-2-butenyl)-2-cyclopentenone (8), respectively. They arise by deacylation of anti-isohumulone (3_a), which is formed from humulone (1a) following an isomerization with ring contraction in opposite direction than the usual one producing isohumulones (2a).     

Synthesis of derivatives of indole and quinoline by the intramolecular catalytic cyclization of allylanilines

An effective method for the isolation of 3-methyl-2-ethylindole and 2,4-dimethyl-quinoline by the intramolecular cyclization of N-(1-methyl-2-butenyl)- and 2-(1-methyl-2-butenyl)anilines under the action of the catalyst PdCl₂ (DMSO)_n was developed. The influence of the nature of the solvent, the temperature, and the concentration of the catalyst on the yield and the ratio of the reaction products was investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 325–327, March, 1986.     

Studies on the syntheses of heteroeyelie compounds. Part DV. Cyclization products of i-substituted 2-benzyl-1,2,5,6-tetrahydropyridines [syntheses of analgesics. Part XXXV]

Treatment of 1,2,5,6-tetrahydro-2-(4-hydroxy- and/or 4-methoxybenzyl)-3,4-dimethyl-I-(3-methyl-2-butenyl)pyridines (IV and V) and 2-(4-methoxybenzyl)-3,4-dimethyl-1-(3-methyl-2-butenyl)-4-piperidinol (X) with acid afforded 9-(4-hydroxy- and/or 4-methoxybenzyl)-4,4,5,6-tetramethyl-1-azabicyelo[3,3,1]non-6-ene (XIII and XIV). In contrast, the corresponding 1-allyl-substituted derivatives VI, VII, and XI were converted into the expected 3-allyl-1,2,3,4,5,6-hexahydro-8-hydroxy- and/or 8-methoxy-6,11-dimethyl-2,6-methano-3-benzazocine (II and III).     

Synthesis of chalcones bearing 2-hydroperoxy-3-methyl-3-butenyl or 2-hydroxy-3-methyl-3-butenyl group from prenylated chalcones

Abstract

Chalcones bearing 2-hydroperoxy-3-methyl-3-butenyl or 2-hydroxy-3-methyl-3-butenyl groups, such as xanthoangelol E (1a), xanthoangelol D (2a), psorachalcone A (2?b), xanthohumol D (2c), and related derivatives were first synthesized by using the ene reaction of prenylated chalcones with singlet oxygen.     

New Furano-sesquiterpenoids from Mediterranean Sponges

A mixture of sponges of the East Pyrenean Mediterranean is shown to contain the known sponge products longifolin ( 1 ), avarol ((+)- 3 ), and avarone ( 4 ) and the terrestrial-plant product sesquirosefuran ( 2 ), besides to the new furano-sesquiterpenoids tavacfuran (= 3-methyl-2-[(3′Z)-3′-methyl-4″-methyl-2″-furyl-3′-butenyl]furan; ( 5 ) and tavacpallescensin (= 5,10-dihydro-6,9-dimethyl-4H-benzo[5,6]cyclohepta[1,2-b]furan; 6 ) and the new furano-butenolide sesquiterpenoids tavacbutenolide-1 (= (±-4-ethoxy-2-methyl-4-)[(2′E)-2′-methyl-4′-(3″-methyl-2″-furyl)-2′-butenyl]-2-buten-4-olide; (±)- 7 ) and tavacbutenolide-2 (= (±)-4-ethoxy-3-methyl-4-[2′E)-3′-methyl-4′-(4″-methyl-2″-furyl)-2′-butenyl]-2-buten-4-olide; (±)- 8 ). Structural assignments are based on NMR data and on the synthesis of the (E)-isomer of 5 . The sponge Dysidea tupha of the same area is also shown to contain the two sesquiterpenoids ent-furodysinin ((?)- 14 ), which is enantiomeric to a product of a Dysidea sp. of Australian waters, and tuphabutenolide ((+)- 15 ).     

Identification and biological activity of microbial metabolites of xanthohumol

Microbial transformation of xanthohumol using the culture broth of Cunninghamella echinulata NRRL 3655 afforded (2S)-8-[4"-hydroxy-3"-methyl-(2"-Z)-butenyl]-4',7-dihydroxy-5-methoxyflavanone (5) and (2S)-8-[5"-hydroxy-3"-methyl-(2"-E)-butenyl]-4',7-dihydroxy-5-methoxyflavanone (6). Xanthohumol (1) and flavanone 6 as well as (E)-2"-(2"'-hydroxyisopropyl)-dihydrofurano[2",3":4',3']-2',4-dihydroxy-6'-methoxychalcone (2), (2S)-2"-(2"'-hydroxyisopropyl)-dihydrofurano[2",3":7,8]-4'-hydroxy-5-methoxyflavanone (3) obtained with Pichia membranifaciens showed antimalarial activity against Plasmodium falciparum.     

Synthetic studies toward miroestrols: trials for elongation of the methyl group of 5-substituted 2-methyl-2-cyclohexanone to 3-methyl-2-butenyl function

Toward total synthesis of miroestrols (miroestrol and deoxymiroestrol), 3-methyl-2-butenyl function (endo-C5 unit) on D ring as a carbon chain for C and E rings was prepared by elongation of the methyl group in α-methyl-α,β-unsaturated ketone unit, and 3,5-dinitrobenzoyl group was introduced as a potential leaving group for the construction of B ring. The former was accomplished through a sequence of epoxide ring-opening, microwave-irradiated siloxy-Cope rearrangement, and isomerization of 3-methyl-3-butenyl function (exo-C5 unit) to endo-C5 unit.     

The acid-catalyzed rearrangement of 1-N-allylindolines

Zinc chloride-catalyzed rearrangement of 1-N-allylindoline and 1-N-(2-methylallyl)indoline proceeds readily in refluxing xylene to give 7-allylindoline and 7-(2-methylallyl)indoline in 73% and 86% yields, respectively. The reaction of 1-N-2-butenylindoline and zinc chloride give rise to the mixture of 7-(1-methylallyl)indoline, 7-(cis- and trans-1-methyl-1-propenyl)indoline, and 7-(trans-2-butenyl)indoline. On the other hand, the similar reaction of 1-N-(3-methyl-2-butenyl)indoline with zinc chloride led to the formation of a mixture of 1,2,5,6-tetrahydro-4,4-dimethyl-4H-pyrrolo[3,2,1-ij]quinoline and 7-(3-methyl-2-butenyl)indoline.     

Iodocyclization of S-allyl derivatives of 3-mercapto-4-methyl-1,2,4-triazole

It has been established that iodocyclization of 3-(2-methyl-2-propenyl)thio-4-methyl-1,2,4-triazole occurs regioselectively with annelation of the thiazole ring, 3-(3-methyl-2-butenyl)thio-4-methyl-1,2,4-thiazole with annelation of the thiazine ring, and 3-allylthio-4-methyl-1,2,4-triazole with annelation of both rings to form derivatives of [1,3]thiazolo[3,2-b][1,2,4]triazolium and [1,2,4]triazole[5,1-b][1,3]thiazinium iodides.     

Stereoselective syntheses of the 2-Isopropenyl-2,3-dihydrobenzofuran nucleus: potential chiral building blocks for the syntheses of tremetone, hydroxytremetone, and rotenone

The first enantioselective synthesis of the 2-isopropenyl-2,3-dihydrobenzofuran skeleton of tremetone and hydroxytremetone from (E)-4-(2-hydroxyphenyl)-2-methyl-2-butenyl methyl carbonate and (E)-4-(2,6-dihydroxyphenyl)-2-methyl-2-butenyl methyl carbonate, respectively, is described. The key step is a catalytic palladium-mediated reaction in the presence of the chiral Trost ligand.     

Amidrazones 11. Rearrangement of 1-allyl-substituted-4,5-dihydro-1-methyl-1H-pyrazolium bromides

1-Methyl-2-(2-propenyl)-3-pyrazolidinimine ( 5 ) was obtained by treatment of 3-amino-4,5-dihydro-1-methyl- 1-(2-propenyl)-1H-pyrazolium bromide ( 4 ) with ethanolic sodium ethoxide. Similar treatment of the analogous 2-(2-butenyl) and 2-(3-phenyl-2-propenyl)-substituted salts 12 and 15 gave 1-methyl-2-(1-methyl-2-propenyl)-3- pyrazolidinimine ( 13 ) and 1-methyl-2-(1-phenyl-1-propenyl)-3-pyrazolidinimine ( 16 ) respectively.     

Synthesis Of 3-(Endo)-[3′Methyl-2′-Buienylsulfonyl]-Camphor by Reaction of the Camphor Enolate with Sulfur Dioxide

The lithium enolate of (+)-camphor reacts with sulfur dioxide and 3-methyl-2-butenyl bromide to produce the β-keto-sulfone 3-(endo)-[3′-methyl-2′-butenyl-sulfonyl]-camphor 4.     

Structures of N-methylnicotone and Py-N-methylmetanicotone

Summary The structures of N-methylnicotone and Py-N-methylmetanicotone are, respectively, 1-methyl-5-(1-methyl-2-pyrrolidinyl)-2(1H)-pyridone and 1-methyl-5-(4-methylamino-1-butenyl)-2(1H)-pyridone.     

Enzyme inhibitory constituents from Duranta repens

Isoprenylated flavonoids 5,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-3,6,4'-trimethoxyflavone (1), 3,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-5,6,4'-trimethoxyflavone (2) and an isoprenylated acetophenone derivative (3) have been isolated from Duranta repens along with known compounds, 5-hydroxy-3,6,7,4'-tetramethoxyflavone (4), rosenonolactone (5), 6,7-dimethoxycoumarin (6), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (7) and 5alpha,8alpha-epidioxyergosta-6,9(11),22-trien-3beta-ol (8), isolated for the first time from this species. Their structures and the relative configuration were determined by spectroscopic methods (1H- and 13C-NMR, IR, UV and MS) and two-dimensional (2D)-NMR experiments. The compounds 1-5 showed inhibitory activity against prolyl endopeptidase while 4 and 5 were also active against thrombin.     

Claisen rearrangement of sterically hindered N-alkenylindolines

Conclusions Claisen rearrangement of N-(1-methyl-2-butenyl)-2-methyl-2-ethylindoline occurs under mild conditions upon treatment with acids at 20°C. Tricyclic compounds, namely, 6,6-dimethylperhydroeyclopent[g]-2-methyl-2-ethylindoline and 8-methyl-8-ethylpyrrolidino[h, i]-3-methyl-2-ethylindole, were obtained from 7-(1-methyl-2-butenyl)-2-methyl-2-ethylindoline.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 613–618, March, 1987.     

1H, 13C and 29Si NMR spectra of allylic trimethylsilanes

Chemical shift and scalar coupling constant data have been obtained for the ¹H, ¹³C and ²⁹Si nuclei in allyl, methally, cis- and trans-crotyl, cis-2-methyl-2-butenyl and 3-methyl-2-butenyl derivatives of trimethylsilane.     

A short synthesis of ishwarone

2,3,4-Trimethyl-2-cyclohexenone can be converted to the corresponding isoprene Diels-Alder adduct by a sequence initiated by conjugate addition of lithium bis(3-methyl-3-butenyl)cuprate; the sesquiterpenoid ishwarone has been synthesized in two steps from the resulting octalone.     

Prenylindoles from Tanzanian Monodora and Isolona species

6-(3-Methyl-but-2-enyl)-1,3-dihydro-indol-2-one, annonidine F [3-[6-(3-methyl-but-2-enyl)-1H-indolyl]-6-(3-methyl-but-2-enyl)-1H-indole], 1H-indole-5-carbaldehyde, 6-(3-methyl-2-butenyl)-1H-indole, 6-(3-methyl-buta-1,3-dienyl)-1H-indole, 6-(4-oxo-but-2-enyl)-1H-indole and 3-geranylindole were isolated from Monodora angolensis (Annonaceae) while 3-(1,1-dimethyl-but-2-enyl)-5-(3-methyl-but-2-enyl)-1H-indole (caulidine A), 4-[3-(1,1-dimethyl-but-2-enyl)-1H-indol-5-yl]-but-3-en-2-one (caulidine B), 5-(3-methyl-2-butenyl)-1H-indole and 5-(3-methylbuta-1,3-dienyl)-1H-indole were obtained from Isolona cauliflora (Annonaceae); structural determination by spectroscopic analysis. Some of the prenylindoles had antifungal and antimalarial activities.