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.     

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%。     

Investigation of the Montmorillonite clay-catalyzed [1,3] shift reaction of 3-methyl-2-butenyl phenyl ether

The [1,3] shift reaction of 3-methyl-2-butenyl phenyl ether was catalyzed more effectively by Montmorillonite K10 clay than Montmorillonite KSF clay, and proceeded with greatest ortho-selectivity in carbon tetrachloride at room temperature.     

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.     

1-甲基-1-乙基-3-丁烯基环戊二烯基稀土二氯化物的 合成与表征

报道了1-甲基-1-乙基-3-丁烯基环戊二烯基稀土二氯化物的合成。用元素分析、质谱、红外光谱和核磁共振表征了这类配合物的组成为[C~5H~4C(CH~3)(C~2H~5)CH~2CH＝CH~2]LnCl~2·MgCl~2·THF[Ln=La(1),Nd(2),Sm(3),Gd(4)]。     

A new coumarin from stem bark of Mesua hexapetala

A new alkylated coumarin derivative, hexapetarin (1) along with three other xanthones, trapezifolixanthone (2), cudraxanthone G (3) and 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4), and four common triterpenoids, friedelin (5), stigmasterol (6), beta-sitosterol (7) and gamma-sitosterol (8) were isolated from the stem bark of Mesua hexapetala (Clusiaceae), a plant, native to Malaysia. The structures of these compounds were elucidated and determined using spectroscopic techniques such as NMR and MS. Anti-inflammatory activity assay indicated hexapetarin (1) to possess moderate anti-inflammatory activity, while 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4) gave very good activity.     

The molecular structure of 4a, 5, 8, 8a-tetrahydro-11, 14-dimethoxy-7-methyl-4a-(3-methyl-2-butenyl)-5, 8a-o-benzeno-1, 4-naphthoquinone

A novel natural product, microphyllone, has been isolated from Ehretia microphylla² together with baurenol and ursolic acid. Spectroscopic techniques, derivative formation and finally X-ray diffraction have been utilized in the structure elucidation of microphyllone. The structure appears to be 4a, 5, 8,8a - tetrahydro -11,14- dihydroxy-7-methyl-4a-(3-methyl-2-butenyl)-5, 8a-o-benzeno-1, 4-naphthoquinone.     

Reaction of 2-(1-methyl-2-butenyl)anilines with polyphosphoric acid

Conclusions Cyclization of 2-(1-methyl-2-butenyl)anilines in polyphosphoric acid proceeds with isomerization of the side chain and leads to indolines and indanes in high yields.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 839–842, April, 1985.     

Synthesis and antibacterial activity of chalcones bearing prenyl or geranyl groups from Angelica keiskei

Chalcones bearing prenyl or geranyl groups from Angelica keiskei, such as 4-hydroxyderricin (1a), xanthoangelol (1e), xanthoangelol F (1f), xanthoangelol H (2), deoxyxanthoangelol H (3), and deoxydihydroxanthoangelol H (4) and their derivatives were synthesized. From the evaluation of antibacterial activity of the synthesized chalcones, 1a, isobavachalcone (1b), 1e, 1f, bavachalcone (5a), and broussochalcone B (5b) were found to inhibit Gram-positive bacteria.     

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).     

1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯的合成

在冰浴条件下, 2-甲基噻吩(1)与液溴反应生成3,5-二溴-2-甲基噻吩(2); 在－78 ℃条件下, 硼酸三丁酯加入2, 得到2-甲基-3-溴-5-硼酸基噻吩(3); 3,4-二氟溴苯与3反应得到2-甲基-3-溴-5-(3,4-二氟苯基)噻吩(4); 在－78 ℃下全氟环戊烯与4反应, 得到一种新的二芳基乙烯类光致变色化合物1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯(DT-1). 用IR, NMR, MS和元素分析确定了化合物DT-1的结构, 并对该化合物的光致变色特性进行了初步研究.     

Synthesis of 2-acetyl-3-methyl-4H-1,4-benzothiazine and its derivatives

Summary 2-Aminothiophenol (1) reacts with 3-chloro-2,4-pentanedione (2) in the presence of pyridine to form 2-acetyl-3-methyl-4H-1,4-benzothiazine (3) in high yields. Reaction of3 with hydrazine gives 4-(2-aminophenylthio)-3,5-dimethylpyrazole (5). Condensation of3 with 4-nitrobenzaldehyde yields the corresponding Schiff base7. Hydroxylamine with benzothiazine3 affords 3,9a-dimethyl-3a, 9a-dihydro-9H-isoxazolo[4,5-b][1,4]benzothiazine (8).

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Synthese von 2-Acetyl-3-methyl-4H-1, 4-benzothiazin und seinen Derivaten

Zusammenfassung 2-Aminothiophenol (1) reagiert mit 3-Chlor-2,4-pentandion (2) in Anwesenheit von Pyridin unter Bildung von 2-Acetyl-3-methyl-4H-1,4-benzothiazin (3) in sehr hoher Ausbeute. Benzothiazin3 kondensiert mit Hydrazin zu 4-(2-Aminophenylthio)-3,5-dimethylpyrazol (5), dessen Aminogruppe reagiert mit 4-Nitrobenzaldehyd zu einer Schiffschen Base (7), die spektroskopisch charakterisiert wurde. Benzothiazin3 mit Hydroxylamin ergibt 3,9a-Dimethyl-3a,9a-dihydro-9H-isoxazolo[4,5-b][1,4]benzothiazin (8). Die Stereochemie der letztgenannten Verbindung wurde ermittelt.

     

Preparation of 5-Cyano-4,6-dimethyl-2H-pyran-2-one and 3-Cyano-5-methoxy-4-methyl-5H-furan-2-one via a One-Pot,Domino-Knoevenagel Process

5-Cyano-4,6-dimethyl-2H-pyran-2-one (1) has been prepared via a simple one-pot domino-Knoevenagel reaction starting from ethyl acetoacetate (2) and cyanoacetone (3). Similarly, a new racemic 3-cyano-5-methoxy-4-methyl-5H-furan-2-one (7) has been prepared from 1,1-dimethoxyacetone (6) and cyanoacetic acid (4). The new alkylidene derivatives (Z/E)-ethyl-4-cyano-3-methylbut-3-enoate (5), (Z/E)-ethyl 5-amino-4-cyano-3-methyl-5-oxopent-3-enoate (9), and (2,2-dimethoxy-1-methylethylidene)malononitrile (11) have been prepared via the Knoevenagel reactions. The easy access to these new compounds in good yields shows that ammonium acetate/acetic acid–catalyzed Knoevenagel reactions and domino-Knoevenagel reactions have a broad scope of application.     

Synthesis of 1,2-bis[2-methyl-5(3,4-difluorophenyl)-3-thienyl] perfluorocyclopentene

2-Methylthiophene (1) was treated at 0°C with liquid bromine to form 3,5-dibromo-2-methylthiophene (2) which reacted with tributyl borate to give 2-methyl-3-bromo-5-boronate thiophene (3) at −78°C. Treatment of 3 with 3,4-difluorobrombenzene gave 2-methyl-3-bromo-5-(3,4-difluorophenyl)thiophene (4). Finally, a novel photochromic dithienylethene compound, 1,2-bis [2-methyl-5(3,4-difluorophenyl)-3-thienyl]perfluorocyclopentene (DT-1), was synthesized by the reaction of 4 with perfluorocyclopentene at −78°C. The compound (DT-1) was characterized by IR, NMR, MS, elemental analysis and its photochromic behavior was also discussed. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(10): 1282–1284 [译自: 有机化学]     

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.     

(R,R)-2,3-Butanediol and (s)-pinanediol allylboronates in chiral synthesis of (2S,3S)-3-methyl-5-hexen-2-ol

(R,R)-Butanediol (dichloromethyl)boronate ( 1 ) with 1 equiv. allylmagnesium halide yields (R,R)-2,3-butanediol (1S)-(1-chloro-3-butenyl)boronate ( 3 ) together with the diallylated product (R,R)-2,3-butanediol (1-allyl-3-butenyl)boronate ( 4 ). The formation of 4 is unprecedented in reactions of α-chloroboronic esters with Grignard reagents. With methylmagnesium bromide 3 yielded (R,R)-2,3-butanediol (1S)-(1-methyl-3-butenyl)boronate ( 5 ), which failed to hydrolyze with water. Hydrolysis of 3 yielded impure α-chloroboronic acid, which was esterified with pinacol and treated with methylmagnesium bromide to form 6 , which with (dichloromethyl)lithium followed by methylmagnesium bromide yielded diastereomeric boronic esters 7 and 8 . Oxidation by hydrogen peroxide yielded (2S,3S)- and (2R,3S)-3-methyl-5-hexen-2-ol ( 9 and 10 , ees unknown). Treatment of (s)-pinanediol allylboronate ( 11 ) with (dichloromethyl)lithium at −100°C followed by zinc chloride at up to 25°C has proceeded in the normal way to form (s)-pinanediol (1S)-(1-chloro-3-butenyl)-boronate ( 12 ), which has been elaborated via 13 , 14 , and 15 to (2S,3S)-3-methyl-5-hexen-2-ol ( 9 ) in 95% de.     

Two new chalcones from Shuteria sinensis

Two new chalcones, 2′,3,4,4′-tetrahydroxy-2-prenylchalcone (1) and 3-methoxy-2′,4,4′-trihydroxy-2-prenylchalcone (2), together with two known compounds, munsericin (3) and 3,4-dihydroxylonchocarpin (4), were isolated from the ethanol extract of the whole plant of Shuteria sinensis. Their structures were identified by spectroscopic analysis methods, such as 1D and 2D NMR, along with HR-MS data. Glucose metabolism activity of four compounds was tested, compounds 3 and 4 showed effect on the glucose consumption of insulin-resistant HepG2 cells.     

Synthesis of 3-geranyl- and 3-prenyl-2,4,6-trihydroxybenzophenone

Biologically active phenyl[3-(3,7-dimethyl-2,6-octadienyl)-2,4,6-trihydroxyphenyl]methanone (2) and phenyl[2,4,6-trihydroxy-3-(3-methyl-2-butenyl)phenyl]methanone (3) were synthesized by an efficient and convenient synthetic sequence. The reaction steps of this synthesis included methylation, Friedel-Crafts acylation, demethylation and geranylation steps.     

Interaction of antimony(III) chloride with thiourea, 2-mercapto-5-methyl-benzimidazole, 3-methyl-2-mercaptobenzothiazole, 2-mercaptopyrimidine,and 2-mercaptopyridine

New antimony(III) chloride complexes with heterocyclic thioamides, thiourea (TU), 2-mercapto-5-methyl-benzimidazole (MMBZIM), 3-methyl-2-mercaptobenzothiazole (MMBZT), 2-mercaptopyrimidine (PMT), 2-mercaptopyridine (PYT) of formulae [SbCl₃(TU)₂] (1), [SbCl₃(MMBZIM)₂] (2), [SbCl₃(MMBZT)₂] (3), [SbCl₃(PMT)₂] (4), [SbCl₃(μ ₂-S)(PYT)₂] (5) were synthesized and characterized by elemental analysis, FT-IR and FT-Raman spectroscopies, and TG-DTA analysis. The crystal structure of 5 was also determined by X-ray diffraction. [C₁₀H₁₀Cl₃N₂S₂Sb] (5) crystallizes in space group C2/c, with a?=?25.0169(10)?Å, b?=?9.7952(3)?Å, c?=?12.9329(5)?Å, β?=?109.702(4)°, and Z?=?8. Crystals of 5 grown from acetonitrile solutions adopt a square-pyramidal geometry. The equatorial plane is formed by three chlorides and one sulfur atom from the thione ligand while the second sulfur is axial. The complexes were evaluated for their biological activities and compared with [SbCl₃(MMI)₂] (6) (MMI?=?2-mercapto-1-methylimidazole) and other isostructural ones. The complexes showed moderate cytostatic activity against murine leukemia cells (L1210), murine mammary carcinoma cells (FM3A), human T-lymphocyte (Molt4/C8, CEM), and human cervix carcinoma (HeLa) cells. The chloro and iodo derivatives show better cytostatic activity than the bromo ones.     

Synthesis of alkenylquinolines and cyclization of (1-methyl-2-butenyl)quinaldines in polyphosphoric acid

The reaction of 2- and 4-alkenylanilines with paraldehyde gave 6- and 8-alkenylquinaldines. Heating 8-(1-methyl-2-butenyl)quinaldines in polyphosphoric acid leads to the formation of tricyclic compounds with isomerization of the alkenyl group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1364–1366, October, 1990.