New,convenient synthesis of 2-alkyl- and 2-vinylpyrazolo[3,4-d]-pyrimidine derivatives

Treatment of 1,3-dimethyl-6-hydrazinouracil with the appropriate dimethylformamide dialkylacetal afforded the, corresponding 2-alkyl-5,7-dimethylpyrazolo[3,4-d]pyrimidine-4,6-(5H,7H)diones. The reaction of 1,3-dimethyl-6-(α-methylbenzylidenehydrazino)uracils with dimethylformamide dimethylacetal or triethyl orthoformate gave the corresponding 5,7-dimethyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)diones, respectively. Similarly, treatment of 1,3-dimethyl-6-(α-methylbenzylidenehydrazino)uraeils with triethyl orthopropionate yielded the corresponding 5,7-dimethyl-3-ethyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)diones.     

Synthesis and transformations of (±)-trans-4aβ(H), saα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one

Hydrogenation of 4,7-dimethylcoumarin ( 1 ) in alkaline medium has been shown to furnish a mixture of (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one ( 2 ), (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one ( 3 ) and (±)-cis-4aα(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one ( 4 ) in 40:25:35:ratio, respectively. The stereochemistry of the major hydrogenation product 2 , has been established by transforming it to p-menthane derivatives e.g. (±)-2 (R)-[2′(R)hydroxy-4′(R) methylcyclohex-(1′S)-yl]propan-1-ol ( 20 ) and (±)-trans-3α,6β-dimethyl-3aβ(H),7aα(H)-octahydrobenzofuran ( 12 ). Starting from a mixture of lactones 2, 3 and 4 , lactone 3 has been obtained in pure state employing a sequence of reactions.     

Furopyridines. VIII. Molecular structure and two-dimensional NMR spectral assignment of 2,14-dimethyl-8aβ-hydroxy-7,10-dioxo-5β,6β-(propano)-6α,8α-(ethanoimino)-trans-perhydroisoquinoline

This paper reports the two-dimensional nmr spectral assignment and the X-ray structural determination of 2,14-dimethyl-8β-hydroxy-7,10-dioxo-5β,6β-(propano)-6α,8α-(ethanoimino)-trans-perhydroisoquinoline V which was obtained from 7,10-dimethyl-2β-hydroxy-14-oxo-2,3-(methanoiminoethano)-3β,4β-(propano)-3,4,5,6,7,8-hexahydro-2H-pyrano[2,3-c]pyridine IV by isomerization with hydrochloric acid. Both the compounds IV and V afforded the same dimethiodide IV -2MeI, while the configurational isomer 2,14-dimethyl-8aβ-hydroxy-7,10-dioxo-5α,6β-(propano)-6α,8α-(ethanoimino)-trans-perhydroisoquinoline III gave monomethiodide III -Mel. The structures of these methiodides were also confirmed by X-ray analysis.     

Reaction of N,N-dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) with 1,3-dimethyl-4-aminouracils. A new “one pot” synthesis of 3-aryl-(and 3-alkyl)-4,6-dimethyl-5,7-dioxo-1,2,3-triazolo[4,5-d]pyrimidines (8-azatheophyllines) via a diazo group transfer process

N,N-Dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) ( 1 ) reacts by diazo group transfer with 1,3-dimethyl-4-aryl-(and alkyl)aminouracils 4 to give, under mild “one pot” reaction conditions, a very good yield of 3-aryl-(and 3-alkyl)-4,6-dimethyl-5,7-dioxo-1,2,3-triazolo[4,5-d]pyrimidines (8-azatheophyllines) 8 . That reaction proceeds, very likely, through formation of non-isolated 4-imino-5-diazouracils 6 .     

Fused s-triazino heterocycles. XVII. 8,13-Dihydro-1,3,7,8,13c-pentaazabenzo[de]naphthacene, 7H-1,3,7,8,11b,12,14-heptaazadibenzo[de,hi]naphthacene and 8H-1,3,7,8,13,14c-hexaazabenzo[4,5]cyclohepta[1,2-a]phenalene,three new ring systems

The reaction of 7,9-dibromo-5-tribromornethyl-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 1a ) with p-toluidine is shown to give 4,6-dibromo-2-t-butyl-8,13-dihydro-13-imino-11-methyl-1,3,7,8,13c-pentaazabenzo[de]naphthacene ( 4 ) in two steps with 7,9 dibromo-2-t-butyl-4-cyano-5-p-toluidino-1,3,6,9b-tetraazaphenalene ( 2b ) as the intermediate product. A related annulation reaction of 1a with N-(5-amino-2,4-dimethylphenyl)trimethylacetamide ( 8 ) leads in two steps to 9,11-dibromo-2,13-di-t-butyl-4,6-dimethyl-7H-1,3,7,8,11b,12,14-heptaazadibenzo[de,hi]naphthacene ( 6 ) with 7,9-dibromo-2-t-butyl-4-cyano-5N-(2,4-dimethyl-5-trimethylacetamidophenyl)amino-1,3,6,9b-tetraazaphenalene ( 2d ) as the intermediate product. In a similar fashion the reaction of 1a with o-phenylenediamine forms 14-amino-4,6-dibromo-2-t-butyl-8H-1,3,7,8,13,14c-hexaazobenzo[4,5]cyclohepta[1,2-a]-phenalene ( 12 ) by way of the intermediate 5-N-(2-aminophenyl)amino-7,9-dibromo-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 2e ). The preparation of N-(2,4-dimethyl-5-nitrophenyl)-trimethylacetamide ( 11 ) and its reduction to N-(5-amino-2,4-dimethylphenyl)trimethylacetamide ( 8 ) is also described.     

Synthesis of the Immunodominant Trisaccharide Related to the Antigen From E. COLI O 126

The trisaccharide derivative methyl 2-O-[4,6-di-O-acetyl-3-O-(2,3,4,6-tetra-O-benzyl-α-D-gal-actopyranosyl)-2-deoxy-2-phthalimido-β-D-gluco-pyranosyl]-4,6-O-benzylidene-β-D-mannopyranoside (12) was obtained when 3-O-(2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl)-4,6-di-Oacetyl-2-deoxy-2-phtha-limido-β-D-glucopyranosyl trichloroacetimidate (8) was allowed to react with methyl 3-O-benzyl-4,6-O-benzylidene-β-D-mannopyranoside (11) in presence of trimethylsilyl triflate. Removal of protecting groups then gave the desired trisaccharide.     

New Triterpenes from the Heartwood of Melaleuca leucadendron L.

Fourteen chemical constituents were isolated from the CHCl₃ soluble portion of the heartwood of Melaleuca leucadendron L. These compounds include β-sitosterol (1) , β-sitostenone (2) , 6-hydroxy-4,6-dimethyl-3-hepten-2-one (3) , naphthalene (4) , squalene (5) , 2α3β-dihydroxyurs-12-en-28-oic acid (6) , 3β-hydroxylup-20(29)-en-27,28-dioic acid (7) , 2α,3β-dihydroxyolean-12-en-28-oic acid (8) , 3β,23-dihydroxyolean-12-en-28-oic acid (9) , 2α,3β,23-trihydroxyolean-12-en-28-oic acid (10) , 3β-trans-p-coumaroyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (11) , and three novel oleanane derivatives 23-trans-p-coumaroyloxy-2α,3β-dihydroxyotean-12-en-28-oic acid (12), 3β-trans-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (13) , and its isomer 3β-cis-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (14) , The three novel compounds were characterized as the two and three O-methylated derivatives, respectively.     

Application of Phenyl 1-Selenoglycosides in the Synthesis of a Cell-Wall Tetrameric Fragment of Proteus Vulgaris Strain 5/43

Abstract

DAST-assisted rearrangement of 3-O-allyl-4-O-benzyl-α-l-rhamnopyranosyl azide followed by treatment of the generated fluorides with ethanethiol and BF₃·OEt₂ gave glycosyl donor ethyl 3-O-allyl-2-azido-4-O-benzyl-2,6-dideoxy-1-thio-α/β-l-glucopyranoside. Stereoselective glycosylation of methyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-β-D-glucopyranoside with ethyl 3-O-allyl-2-azido-4-O-benzyl-2,6-dideoxy-1-thio-α/β-l-glucopyranoside, under the agency of NIS/TfOH afforded methyl 3-O-(3-O-allyl-2-azido-4-O-benzyl-2,6-dideoxy-α-l-glucopyranosyl)-4,6-O-benzyli-dene-2-deoxy-2-phthalimido-β-D-glucopyranoside. Removal of the allyl function of the latter dimer, followed by condensation with properly protected 2-azido-2-deoxy-glucosyl donors, in the presence of suitable promoters, yielded selectively methyl 3-O-(3-O-[6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-α-D-glucopyranosyl]-2-azido-4-O-benzyl-2,6-dideoxy-α-l-glucopyranosyl)-4,6-O-benzylidene-2-deoxy-2-phthalimido-β-D-glucopyranoside. Deacetylation and subsequent glycosylation of the free HO-6 with phenyl 2,3,4,6-tetra-O-benzoyl-1-seleno-β-D-glucopyranoside in the presence of NIS/TfOH furnished a fully protected tetrasaccharide. Deprotection then gave methyl 3-O-(3-O-[6-O-{β-D-glucopyranosyl}-2-acetamido-2-deoxy-β-D-glucopyranosyl)-2-acetamido-2,6-dideoxy-α-L-glucopyranosyl)-2-acetamido-2-deoxy-β-D-glucopyranoside.     

Synthesis of Neu5Ac α-(2→ 8)Neu5Ac α-(2→ 3)Galβ1→ Och2Ch2Ch3, A Determinant Epitope of Gd3 Ganglioside

ABSTRACT

Synthesis of the terminal trisaccharide sequence of the ganglioside GD₃, α-D-Neup5Ac-(2→8)-α-D-Neup5Ac-(2→3)-β-D-Galp-(1→4)-β-D-Glcp-(1→1)-Cer (2) was achieved by employing an α-(2→8) disialyl glycosyl donor (1). Condensation of 1 with the glycosyl acceptor 6, propyl 4,6-O-benzylidene-β-D-galactopyranoside, gave the desired protected trisaccharide 10 (14%) as well as the elimination and hydrolysis products of 6, compounds 8 and 9 respectively. O-Deacetylation and debenzylation of 10 gave the final trisaccharide 11, as its propyl glycoside.     

2-Deoxy-2-C-(2,3-dideoxy-α-d-erythro-hexopyranosyl)-β-d-glucopyranoses: Reinvestigation of Synthesis,Use in Glycosylation,and Conformational Analyses by NMR

Abstract

Conformational investigations using 1D TOCSY and ROESY ¹H NMR experiments on 1,3,4,6-tetra-O-acetyl-2-C-(4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hexopyranosyl)-2-deoxy-β-D-glucopyranose (8) and related disaccharides showed that for steric reasons the C-linked hexopyranosyl ring occurs in the usually unfavoured ¹C₄ conformation and reconfirmed the structure of 1,3,4,6-tetra-O-acetyl-2-C-(4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranosyl)-2-deoxy-β-D-glucopyranose (5). Glycosylation of 2,3,6-tri-O-benzyl-α-D-glucopyranosyl 2,3-di-O-benzyl-4,6-(R)-O-benzylidene-α-D-glucopyranoside (13) with acetate 8 using trimethylsilyl triflate as a catalyst afforded the α-D-linked tetrasaccharide 14. A remarkable side product in this reaction was the unsaturated tetrasaccharide 2,3,6-tri-O-benzyl-4-O-[4,6-di-O-acetyl-2,3-dideoxy-2-C-(4,6-di-O-acetyl-2,3-dideoxy-β-D-erythro-hexopyranosyl)-α-D-erythro-hex-2-enopyranosyl]-α-D-glucopyranosyl 2,3-di-O-benzyl-4,6-(R)-O-benzylidene-α-D-glucopyranoside (16) where in the C-linked hexopyranosyl ring an isomerization to the β-anomer had taken place to allow for the favoured ⁴C₁ conformation. The tetrasaccharide 14 was deacetylated and hydrogenolyzed to form the fully deprotected tetrasaccharide 18. The ¹ C ₄ conformation of the C-glycosidic pyranose of this tetrasaccharide was maintained as shown by an in depth NMR analysis of its peracetate 19.     

Synthesis of 4,6-disubstituted-7-β-D-ribofuranosyl- and arabinofuranosylpyrazolo[3,4-d]pyrimidines and certain related ribonucleosides

Several disubstituted pyrazolo[3,4-d]pyrimidine, pyrazolo[1,5-a]pyrimidine and thiazolo[4,5-d]pyrimidine ribonucleosides have been prepared as congeners of uridine and cytidine. Glycosylation of the trimethylsilyl (TMS) derivative of pyrazolo[3,4-d]pyrimidine-4,6(1H,5H,7H)-dione ( 4 ) with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose ( 5 ) in the presence of TMS triflate afforded 7-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)pyrazolo-[3,4-d]pyrimidine-4,6(1H,5H)-dione ( 6 ). Debenzoylation of 6 gave the uridine analog 7-β-D-ribofuranosylpyrazolo[3,4-d]pyrimidine-4,6(1H,5H)-dione ( 3 ), identical with 7-ribofuranosyloxoallopurinol reported earlier. Thiation of 6 gave 7 , which on debenzoylation afforded 7-β-D-ribofuranosyl-6-oxopyrazolo[3,4-d]pyrimidine-4(1H,5H)-thione ( 8 ). Ammonolysis of 7 at elevated temperature gave a low yield of the cytidine analog 4-amino-7-β-D-ribofuranosylpyrazolo[3,4-d]pyrimidin-6(1H)-one ( 11 ). Chlorination of 6 , followed by ammonolysis, furnished an alternate route to 11 . A similar glycosylation of TMS-4 with 2,3,5-tri-O-benzyl-α-D-arabinofuranosyl chloride ( 12 ) gave mainly the N7-glycosylated product 13 , which on debenzylation provided 7-β-D-arabinofuranosylpyrazolo[3,4-d]pyrimidine-4,6(1H,5H)-dione ( 14 ). 4-Amino-7-β-D-arabinofuranosyl-pyrazolo[3,4-d]pyrimidin-6(1H)-one ( 19 ) was prepared from 13 via the C4-pyridinium chloride intermediate 17 . Condensation of the TMS derivatives of 7-hydroxy- ( 20 ) or 7-aminopyrazolo[1,5-a]pyrimidin-5(4H)-one ( 23 ) with 5 in the presence of TMS triflate gave the corresponding blocked nucleosides 21 and 24 , respectively, which on deprotection afforded 7-hydroxy- 22 and 7-amino-4-β-D-ribofuranosylpyrazolo[1,5-a]pyrimidin-5-one ( 25 ), respectively. Similarly, starting either from 2-chloro ( 26 ) or 2-aminothiazolo[4,5-d]pyrimidine-5,7-(4H,6H)-dione ( 29 ), 2-amino-4-β-D-ribofuranosylthiazolo[4,5-d]pyrimidine-5,7(6H)-dione ( 28 ) has been prepared. The structure of 25 was confirmed by single crystal X-ray diffraction studies.     

Synthesis of amino derivatives of triazolopyrimidine

Heterocyclization of 1-(4,6-dimethylpyrimidin-2-yl)-4-R-thiosemicarbazides by the action of methyl iodide in ethanol in the presence of sodium acetate is accompanied by Dimroth rearrangement leading to the formation of 5,7-dimethyl-2-R-amino[1,2,4]triazolo[1,5-a]pyrimidines. Analogous heterocyclization of 4-aryl-1-(4-methyl-6-oxo-1,6-dihydropyrimidin-2-yl)thiosemicarbazides gives 3-arylamino-7-methyl-5-oxo-[1,2,4]triazolo[4,3-a]pyrimidines. The presence in the pyrimidine ring of a carbonyl group capable of forming hydrogen bond with protons of the amino group stabilizes the molecule, thus hampering the Dimroth rearrangement.     

Synthesis of Four Spacer-Containing Trisaccharides with the 4-0-(β-L-Rhamnopyranosyl)-D-glucopyranose Unit in Common,Representing Fragments of Capsular Polysaccharides from Streptococcus Pneumoniae Types 2, 7F, 22F,and 23F

Abstract

The synthesis is reported of 3-aminopropyl 3-O-[4-O(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-α-L-rhamnopyranoside (34), 3-aminopropyl 2-acetamido-3-O-[4-0-(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-2-deoxy-β-D-galactopyranoside (37), 3-aminopropyl 3-O-[4-O-(β-L-rhamnopyranosyl)-α-D-glucopyranosyl]-α-D-galactofuranoside (41), and 3-aminopropyl 4-O-[4-O-(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-galactopyranoside (45). These are spacer-containing fragments of the capsular polysaccharides of Streptococcus pneumoniae type 2, 7F, 22F, and 23F, respectively, which are constituents of Pneumovax^© 23. 2,3,4-Tri-O-benzyl-α-L-rhamnopyranosyl bromide was coupled to l,6-anhydro-2,3-di-(O-benzyl-β-D-glucopyranose (3). Opening of the anhydro ring, removal of AcO-1, and imidation of l,6-anhydro-2,3-di- O-benzyl-4-O-(2,3,4-tri-O-benzyl-β-L-rhamnopyranosyl)-β-D-glucopyranose (4β) afforded 6-O-acetyl-2,3-di-O-ben-zyl-4-O-(2,3,4-tri- O-benzyl-β-L-rhamnopyranosyl)-αβ-D-glucopyranosyl trichloroacet-imidate (7αβ). Condensation of 7αβ with 3-N-benzyloxycarbonylaminopropyl 2-O-ben-zyl-5,6-O-isopropylidene-α-D-galactofuranoside (26), followed by deprotection gave 41 Opening of the anhydro ring of 4 p followed by debenzylation, acerylauon, removal of AcO-1, and imidation yielded 2,3,6-tri-(9-aceryl-4-O-(2,3,4-tri-0-acetyl-P-L-rharnnopyran-.-osyl)-α-D-glucopyranosyl trichloroacetimidate (11). Condensation of 11 with 3-N-bcn-zyloxycarbonylaminopropyl 2,4-di-O-benzyl-α-L-rhamnopyranoside (18), with 3-N-bcn-zyloxycarbonylaminopropyl 2-acetamido-4,6-O-benzylidene-2-deoxy-β-D-galactopyran-oside (21), or with 3-N -benzyloxycarbonylaminopropyl 2-O-acetyl-3-O-allyl-6-O-benzyl-β-D-galactopyranoside (31), followed by deprotection afforded 34, 37, and 45, respectively.     

Synthesis and xanthine oxidase inhibitory activity of 4,6-disubstituted 1-p-chlorophenylpyrazolo[3,4-d]pyrimidines

Several 4,6-disubstituted 1-p-chlorophenylpyrazolo[3,4-d]pyrimidines were prepared from 4,6-dichloro-1-p-chlorophenylpyrazolo[3,4-d]pyrimidine and their xanthine oxidase inhibitory activity were tested in vitro.     

Pyrimidines. 24. Analogues and derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP)

Preparation of a number of derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP) including the 2-dialkylaminoalkylamino-, 2-hydroxyalkylamino-, 2-ethoxycarbonylamino- and 2-alkylaminocarbonyl-amino- groups substituted on the pyrimidine ring as well as preparation of 1-(alkylaminoalkyl)-4,6-dioxo-8-phenyl-2,3,4,6-tetrahydro-1H-pyrimido[1,2-α]pyrimidines and 3,5-dioxo-7-phenyl-1,2,3,5-tetrahydroimidazo-[1,2-α]pyrimidines with or without the bromo-substitution are reported.     

The Synthesis of Four Dideoxygenated Analogues of β-Maltosyl-(1→4)-Trehalose

Abstract

Four derivatives of β-maltosyl-(1→4)-trehalose were prepared, each with two deoxy functions in one of the constitutive disaccharide building blocks. 2,3-Di-O-acetyl-4,6-dideoxy-4,6-diiodo-α-D-galactopyranosyl- (1→4) ?1,2,3,6-tetra-O-acetyl-D-glucopyranose (3) was employed as a precursor for the 4?,6?-dideoxygenated tetrasaccharide 9: coupling of 3 with 2,3,6-tri-O-benzyl-α-D-glucopyranosyl 2,3,6-tri-O-benzylidene-α-D-glucopyranoside (4) furnished the tetrasaccharide 5 which was deiodinated and deprotected to yield the target tetrasaccharide 9. Secondly, the dideoxygenated maltose derivative 3-deoxy-4,6-O-isopropylidene-2-O-pivaloyl-β-D-glucopyranosyl- (1→4) ?1,6-anhydro-3-deoxy-2-O-pivaloyl-β-D-glucopyranose (10) was ring-opened to the anomeric acetate 11. A [2+2] block synthesis with 4 in TMS triflate mediated glycosylation gave a tetrasaccharide which was deprotected to the 3″,3?-dideoxygenated analogue of β-maltosyl-(1→4)-trehalose. For the third tetrasaccharide, 2,3,2″,3′-tetra-O-benzyl-α,α-trehalose was iodinated at the primary positions and deiodinated in the presence of palladium-on-carbon, then this acceptor was selectively glycosylated with hepta-O-acetyl-maltosyl bromide (20). Removal of protective groups furnished the maltosyl trehalose tetrasaccharide deoxygenated at positions C-6 and C-6′. to prepare a 3,3′-dideoxygenated trehalose, the free hydroxyl groups of 2-O-benzyl-4,6-O-(R)-benzylidene-α-D-glucopyranosyl 2-O-benzyl-4,6-O-(R)-benzylidene-α-D-glucopyranoside (25) were reduced by Barton-McCombie deoxygenation. One of the benzylidene groups was opened reductively with sodium cyanoborohydride. The resulting free hydroxyl group at the 4′-position was glycosylated in a Koenigs-Knorr reaction with 20 to yield the 3,3′-dideoxygenated tetrasaccharide 32, the fourth target oligosaccharide, after deprotection.     

香菇多糖核心片段六糖的合成研究

以已知的2,3,4,6-四-O-苯甲酰基--D-葡萄吡喃糖-(13)-[2,3,4,6-四-O-苯甲酰基-β-D-葡萄吡喃糖-(16)]-2,4- 二-O-乙酰基-β-D-葡萄吡喃糖-(13)-2,4,6-三-O-乙酰基-α-D-葡萄吡喃糖三氯乙酰亚胺酯(2)为供体, 以2-O-苯甲酰 基-4,6-O-苄叉基-α-D-葡萄吡喃糖烯丙基苷(4)作为受体, 立体专一性地偶联得到β-1,3连接的五糖5. 五糖5酸解脱去4,6-苯亚甲基基后与2,3,4,6-四-O-苯甲酰基-α-D-葡萄吡喃糖三氯乙酰亚胺酯(7)偶联, 区域和立体专一性地得到全保护的β-1,3主链β-1,6支链的六糖8. 六糖8脱保护后得到目标化合物香菇多糖核心片段六糖9. 发展了合成该类化合物的一种新方法.     

Heterocyclization of Oximes of 3,5-Dimethyl(1,3,5-trimethyl)-2,6-diphenylpiperid-4-ones and N-Benzylpyrrolid-3-ones with Acetylene in a Superbasic Medium

It has been established that on heterocyclization of 3,5-dimethyl-2,6-diphenylpiperid-4-one oxime with acetylene in a superbasic medium migration of the 3a-CH₃ group to the anionic nitrogen atom occurs, leading to the formation of 5,7-dimethyl-4,6-diphenyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridine. The formation of the N-anion causes aromatization of the tetrahydropyridine ring. Tetrahydropyrrolo[1,2-c]pyrimidines are formed in the Trofimov reaction as a result of decomposition of the intermediate 3H-pyrrole in a retro-Mannich reaction.     

Anatolioside E: A New Acyclic Monoterpene Glycoside from Viburnum orientale

A new open-chain monoterpene glycoside, anatolioside E ( 1 ), was isolated from the leaves of Viburnum orientale in addition to three known acyclic monoterpene glycosides, betulalbusides A ( 2 ) and B ( 3 ), and 2(E)-2,6-dimethyl-2,7-octadien-1,6-diol-6-O-β-D -glucopyranoside( 4 ). The structure of anatolioside E ( 1 ) was elucidated on the basis of chemical and spectral data as 6-O-[β-D -glucopyransoyl-(1?? → 6?″)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1?″ → 2″″)-β-D -glucopyranosyl-(1″″ → 6?)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1? → 4″)-α-L -rhamnopyranosyl-(1″″ → 2′)-β-D -glucopyranosyl]linalool.     

Study on the Reaction of CIS-1-Acetyl-2-Aryl-6,6-Dimethyl-5,7-Dioxospiro-[2,5]-4,8-Octadiones with Methanol

Cis-l-acetyl-2-aryl-6,6-dimethyl-5,7-dioxo-spiro-[2,5]-4,8-octadiones 3a-d (X=p-CH₃, p-Cl, H, p-NO₂) reacted with anhydrous methanol in a sealed tube at 80°C to form trans, cis-α-carbomethoxy-β-(α′-methoxy-α′-aryl)-γ-methoxy-γ-methyl-γ-butyrolactones 4a-d and cis, cis-α-carbomethoxy-β-(α′-methoxy-α′-aryl)-γ-methoxy-γ-methyl-γ-butyrolactones 5a-d in good yield.