Transformations of isomeric naphthopyranones. The synthesis of substituted β-naphthyl-α,β-dehydro-α-amino acid derivatives

The opening of the pyranone ring in 2H-naphtho[1,2-b]pyran-2-one derivative (1) and 3H-naphtho[2,1-b]-pyran-3-one derivatives 8 and 20 with nucleophiles afforded 3-(naphthyl-1)- and 3-(naphthyl-2)propenoates (substituted β-naphthyl-α,β-dehydro-α-amino acid derivatives) 7, 13, 14, 15, 24 , and 35 .     

A facile synthesis of 1-alkylthio and acylthio-2,3-dihydro-1H-naphtho[2,1-b]thiopyrans and 4-alkylthio and acylthio-3,4-dihydro-2H-naphtho[1,2-b]thiopyrans

The reaction of 3-(2-naphthylthio)propionaldehyde ( 3 )and its (1-naphthylthio)isomer (7)with a variety of thiols and thio acids in the presence of sulfuric acid at room temperature afforded 1-alkylthio and acylthio-2,3-dihydro-1H-naphtho[2,1-b]thiopyrans 5 and 4-alkylthio and acylthio-3,4-dihydro-2H-naphtho[1,2-b]thiopyrans 9 in excellent yield.     

The synthesis and transformations of 2H-naphtho-[1,2-b]pyran-2-one derivatives. Naphtho[2′,1′:5,6]-pyrano[3,4-d][1,3]oxazines and naphtho[1′,2′:5,6]pyrano[3,4-d]-pyrimidines,derivatives of two new heterocyclic systems

1,4-Naphthoquinone ( 1 ) was transformed with alkyl 2-aminofumarates 2 into 2H-naphtho[1,2-b]pyran-2-ones 3 and 4 , which served as intermediates in the synthesis of 7, 8 and 13 , which are derivatives of two new heterocyclic systems: naphtho[2′,1′:5,6]pyrano[3,4-d][1,3]oxazine and naphtho[1′,2′:5,6]pyrano[3,4-d]pyrimidine.     

Thiophene systems. 13. The synthesis of novel thienopyranones

The syntheses and spectral properties of novel dimethyl-substituted thieno[3,2-b]-, [3,4-b]- and [2,3-b]pyran-ones are described. The uv spectra of the three systems are distinctly different as supported by HOMO/LUMO calculations. 5,6-Dihydro-5,5-dimethyl-7H-thieno[3,4-b]pyran-7-one ( 10 ) and 5,6-dihydro-6,6-dimethyl-4H-thieno[2,3-b]pyran-4-one ( 20 ) represent the first members of these thienopyranone ring systems.     

Anthranilic acid hydrazide in the synthesis of fused polycyclic compounds with quinazoline moieties

A modified procedure was developed for the synthesis of 5,6,7,8,13,13a-hexahydrophthalazino[1,2-b]quinazoline-5,8-dione and 6-amino-5,6,6a,11-tetrahydroisoindolo[2,1-a]quinazoline-5,11-dione from o-formylbenzoic acid and anthranilic acid hydrazide. The mechanism of the transformation is suggested, some reactions were studied, and new derivatives of these compounds were synthesized. Anthranilic acid hydrazide was used in the novel synthesis of 5-substituted phthalazino[1,2-b]quinazolin-8-one derivatives. The possible reaction mechanism is discussed. 5,6,7,8-Tetrahydrophthalazino[1,2-b]quinazoline-5,8-dione and 5-phenylphthalazino[2,1-b]quinazolin-8-one were studied by X-ray diffraction.     

The reaction between 3,3-bis(methoxyphenyl)-3H-naphtho[2,1-b]pyran and 1,3-bis(methoxyphenyl)-1H-naphtho[2,1-b]pyran, 2,2-diphenyl-2H-chromen and 2,4-diphenyl-4H-chromen,and related compounds

The reaction between 3,3-bis(methoxyphenyl)-3H-naphtho[2,1-b]pyran and 1,3-bis(methoxyphenyl)-1H-naphtho[2,1-b]pyran under acid conditions gives a 7a,15a-dihydro-7a,15-bis(methoxyphenyl)-16-[2,2-bis(methoxyphenyl)-l-vinyl]dinaphtho-[2,1-b:2,1-g]-4H,5H-pyrano[2,3-b]-pyran.     

Synthesis of spiro[2H-indole-2,1′-1H-isoindole]-3,3′-diones,spiro[1H-isobenzofuran-1,2′-2H-indole]-3,3′-diones and spiro[benzofuran-2,1′-isobenzofuran]-3,3′-diones via transannular reactions of eight membered ring intermediates

An auto oxidation-rearrangement product 4 was isolated from a high dilution reaction of ninhydrin with 3,4,5-trimethoxyaniline in water. A general synthesis of this compound and its derivatives 4–6 was devised by oxidation of tetrahydroindeno[1,2-b]indol-10-ones 1–3 with sodium periodate to give isoindolo[2,1-a]-indole-6,11-diones 4–6 in good yield. Compounds 4–6 can be easily transformed into spiro[1H-isobenzofuran-1,2′-2H-indole]-3,3′-diones 8–10 , spiro[2H-indole-2,1′-1H-isoindole]-3,3′-diones 11–13 and isoindole[1,2-a:2′,1′-b]pyrimidine-5,15-diones 15, 16 in high yields. Analogous reactions were performed on 3-amino-5a, 10a-dihydroxybenzo[b]indeno[2,1-d]furan-10-one ( 17 ) to give a dibenzoxocintrione 18 , spiro-[benzofuran-2,1′-isobenzofuran]-3,3′-dione 19 and an isoindol-1-one 20 .     

2,2′-Bifurylidene-5,5′-diones,Coumarins, 3a, 7a-dihydro-1H-inden-1-ones,and 5H-furo[3,2-b]pyran-5-ones from propyne and carbon monoxide

The [Co₂ (CO)₈]-catalyzed reaction between propyne and CO in acetone at 110° and 170 bar was re-investigated. There are five major products: (E)-3,4′-dimethyl-2,2′-bifurylidene-5,5′-dione ( 4 ), 3,5,8-trimethylcoumarin ( 8 ), 3a, 7a-dihydro-2,4,7,7a-tetramethyl-1H-inden-1-one ( 9 ), 2,6-dimethyl-5H-furo [3,2, -b]- pyran-5-one ( 11 ), and 2,7-dimethyl-5H-furo 3,2-b-pyran-5-one ( 12 ); of these, only one, 4 . had previously been recognized. In parallel experiments were obtained 2,6-dipentyl-5 H-furo[3,2-b]pyran-5-one ( 13 ), 2,7-dipentyl–5H-furo[3,2-b]pyran-5-one ( 14 ), 3a, 7a-dihydro-2,4,7,7a-tetrapentyl-1H-inden-1-one ( 15 ). And 3a, 7a-dihydro-2,4,6,7a-tetrapentyl-1H-inden-1-one ( 16 ) from hept-1-yne, and two further types of products from two atypical 1-alkynes: 3,6,9-tri(tert-butyl)-1-oxaspiro[4.4]nona-3,6,8-trien-2-one ( 20 ) from (tert-butyl)acetylene and the exo-dimer 21 of 2,5-bis(trimethylsilyl)cyclopenta-2,4-dien-1-one ( 22 ) from (trimethylsilyl)acetylene. Compounds 11,12 , and 20 were identified by X-ray analysis.     

12H-naphtho[1′,2′:5,6]pyrano[2,3-d]pyrimidine derivatives

Reaction of 1-oxo-2-formyl-3-dimethylamino-1H-naphtho[2,1-b]pyran with amidines, guanidine, O-methylisourea, S-methylisothiourea afforded 9-substituted 12-oxo-12H-naphtho[1′,2′:5,6]pyrano[2,3-d]pyrimidines. When the reaction with O-methylisourea was carried out in anhydrous pyridine, 10,20-dioxo-10H,20H-dinaphtho[1,2-e:1′,2′-e′][1,5]diazocino[2,3-b:6,7-b′]dipyran was formed.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. XVIII. Synthesis of N,N-disubstituted 4-amino-3-phenyl-2H-naphtho[1,2-b]pyran-2-ones

1,4-Cycloaddition of phenylchloroketene to N,N-disubstituted 2-aminomethylene-3,4-dihydro-1(2H)naphthalenones gave the corresponding adducts, namely N,N-disubstituted 4-amino-3-chloro-3,4,5,6-tetrahydro-3-phenyl-2H-naphtho[1,2-b]pyran-2-ones II, in the case of aliphatic N,N-disubstitution or aromatic N-monosubstitution. Apart from IIf (NR₂ = NMePh), adducts II were unstable and were dehydrochlorinated in situ with DBN to give N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-naphtho[1,2-b]pyran-2-ones III in fair overall yields. Compounds III were dehydrogenated with Pd/C in boiling p-cymene to afford the title compounds generally in high yields.     

A Novel,Degraded Polyketidic Lactone,Leptosphaerolide, and Its Likely Diketone Precursor,Leptosphaerodione. Isolation from Cultures of the Marine Ascomycete Leptosphaeria oraemaris (LINDER)

Acetone extraction of cultures of the marine ascomycete Leptosphaeria oraemaris (LINDER) on cornmeal disk gave the novel polyketide derivative leptosphaerolide ( = (+)-7-[(1E)-l,3-dimethylpent-1-enyl]-10-hydroxy-3-methoxybenzo[1,2-b:5,4-c′]dipyran-2(9H)-one; (4+)-8) besides the o-dihydroquinone 3-[(1E)-1,3-dimethylpent-1-euyl]-8,10-dihydroxy-7-methoxy-8-(2-oxopropyl)-1H-naphtho[2,3-c]pyran-9(8H)-one ( 1 ) as a 10:9 mixture of epimers. retro-Aldol reaction of 1 gave leptosphaerodione ( = (?)-3-[(1E)-1,3-dimethylpent-1-enyl]-10-hydroxy-7-methoxy-1H-naphtho[2,3-c]pyran-8,9(8H)-dione; (?)-6) which was also present in small amounts in the extracts and which gave 1 on reaction with acetone. It is thus likely that 1 is an artefact of the extraction by acetone. Biogenetically (+)-8 might derive from (?)-6 via an unusual oxidation with loss of CO₂.     

Synthesis of a rotenone-like benzopyranobenzopyranone

The synthesis of a novel rotenone-like molecule, 9-methoxy-8-methyl-6,6a,12,12a-tetrahydro[1]benzopyrano-[3,4-b][1]benzopyran-12-one ( 2 ) is described. Efficient syntheses of 3,4-dihydro-2H-[1]benzopyran-3-one ( 9 ) from ethyl 3-hydroxy-2H-[1]benzopyran-4-carboxylate ( 6 ), an intermediate in the synthesis of 2 , were developed. Thermolysis of 6 and 9 in decalin yielded 6,8-dihydro-14H-bis[1]benzopyrano[3,4-b:4′,3′-e]pyran-14-one ( 8 ), which has previously been described. Also produced in the thermolysis was the isomeric 1H-bis[1]-benzopyrano[3,4-b:3′,4′-á]pyran-7-(9H)one ( 10 ), the first member of a novel, pentacyclic ring system.     

Bis-Pyrazolones as azodienophiles

Lead tetraacetate oxidations of 2,3,3a,4,6,7,7a,8-octahydrobenzo[1,2-c:4,5-c']dipyrazolo-3,7-dione and 2,3,3a,4,5,5a,6,7-octahydrobenzo[2,1-c:3,4-c']dipyrazolo-3,6-dione in the presence of 1,3-cyclopentadiene, 1,3-cyclohexadiene, 2,3-dimethyl-1,3-butadiene or 1,4-diphenyl-1,3-butadiene have yielded octahydrodipyridazino[1,2-a:1,2-a']benzo[1,2-c:4,5-c']dipyrazolo-6,14-diones and octahydrodipyridazino[1,2-a:1,2-a']benzo[2,1-c:3,4-c']dipyrazolo-6,9-diones. In one of the eight Diels-Alder reactions two isomeric products were isolated.     

New heterocyclic structures. [1,2,5]Thiadiazolo[3′,4′:4,5]pyrimido-[2,1-b][1,3]thiazine and thiazolo[3,2a][1,2,5]thiadiazolo[3,4-d]pyrimidine

Derivatives of two new molecular structures, namely, 7,8-dihydro-6H,10H-[1,2,5]thiadiazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazin-10-one and 6,7-dihydro-9H-thiazolo[3,2-a][1,2,5]thiadiazolo[3,4-d][pyrimidin-9-one, and derivatives of N-substituted sulfamic acid, namely, (8-amino-3,4-dihydro-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-on-7-yl)sulfamic acid and (7-amino-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidin-5-on-6-yl)sulfamic acid, were separated out as by-products in the reduction reaction of 8-amino-3,4-dihydro-7-nitroso-2H,6H-pyrimido[2,1- b][1,3]thiazin-6-one and 7-amino-2,3-dihydro-6-nitroso-5H-thiazolo[3,2-a]pyrimidin-5-one derivatives, respectively, with sodium hydrosulfite. A mechanism of reaction, which hypothesizes the action of sodium hydrosulfite in an asymmetic form, is proposed. The results of single-crystal X-ray investigation on 7,8-dihydro-6H,10H-[1,2,5]thiadiazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazin-10-one (R = 0.032 for 863 reflections) and (8-amino-3,4-dihydro-2H,6H-pyrimido[2,1-b]- [1,3]thiazin-6-on-7-yl)sulfamic acid, sodium salt (R = 0.028 for 3507 reflections) are reported.     

Solid-phase synthesis of 4H-2-(3-hydroxy-4-methoxyphenyl)-naphtho[1,2-b]pyran-1-one

An effective solid-phase preparation of the pharmaceutically interesting 4H-2-(3-hydroxy-4-methoxyphenyl)-naphtho[1,2-b]pyran-1-one system from an anchored bisarylacetylene is described.     

Heterocyclic fused tropylium ions VII. On the synthesis of 9H-dithieno[2,1 -b:4,5-c′]tropylium fluoborate and 4H-dithieno[1,2-b:4,5-c′]tropylium fluoborate

9H-Dithieno[2,1 -b:4,5-c′]tropylium ion (III) and 4ii-dithieno[1,2-b:4,5-c′]tropylium ion (IV) have been synthesized by ring-closure of 1-(4-carboxy-3-thienyl)-2-(3′-thienyl)ethane (IX) and 1-(4-carboxy-3-thienyl)-2-(2′-thienyl)ethane (XVI), respectively, followed by bromination-debrom-ination to 9H-cyclohepta[2,1-b:4,5-c′] dithiophen-9-one (XI) and 4H-cyclohepta[1,2-b:4,5-c′]-dithiophen-4-one (XVIII), and finally by reduction and hydride transfer. The tropylium ions III and IV were less stable than the [b,b′]-fused isomers previously studied.     

An Efficient One-Pot Synthesis Of Dialkyl 3H-Naphtho[2,1,b]pyran-2,3-dicarboxylates Mediated by Vinyl Triphenylphosphonium Salt∗

Protonation of the reactive intermediates produced in the reaction between dialkyl acetylenedicarboxylates and triphenylphosphine by 2-hydroxy-1-naphthaldehyde leads to vinyltriphenylphosphonium salts, which undergo intramolecular Wittig reaction to produce dialkyl 3H-naphtho[2,1-b]pyran-2,3-dicarboxylates in fairly high yields.

     

[3,4]-annulated pyrroles 1. Polynuclear heterocyclic systems based on pyrrolo[3,4-d]pyrimidine-2,4-dione

The intramolecular electrophilic substitution in 6-functionalized 1,3-dimethyl-1H-pyrrolo[3,4-d]pyrimidine-2,4(3H,6H)-diones was used for the synthesis of pyrimido[4′,5′:3,4]-pyrrolo[1,2-a]quinoxaline-8,10(7H,9H)-dione, pyrimido[4′,5′:3,4]pyrrolo[2,1-c][1,2,4]benzo-triazine-8,10(7H,9H)-dione, and 2H-pyrimido[4′,5′:3,4]pyrrolo[1,2-a]indole-2,4,11(1H, 3H)-trione derivatives. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2180–2185, December, 2006.     

Cyclization reactions of 1,3-dibromopropan-2-ol, 2,3-dibromopropan-1-ol and 1-bromomethyloxirane with 6-amino-2,3-dihydro-2-thioxo-4(1H)-pyrimidinone

The cyclization reactions, carried out in strongly- or weakly-basic media, are described. Sometimes, 7-amino-2,3-dihydro-3-hydroxymethyl-5H-thiazolo[3,2-a]pyrimidin-5-one is separated out, together with 8-amino-3,4-dihydro-3-hydroxy-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one, as the principal product. A mechanism of reaction, during which the cyclizating agents are changed into oxirane derivatives, is proposed. The results of single-crystal X-ray investigations on 8-amino-3,4-dihydro-3-hydroxy-7-nitroso-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one (R = 0.035 for 1013 reflections), and on 7-hydroxymethyl-6,7-dihydrothiazolo[3,2-a][1,2,3]triazolo[4,5-d]pyrimidin-9(1H)-one (R = 0.027 for 1607 reflections) are reported.     

Unambiguously confirmed structure of 2-phenacylidene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one and 3-phenacylidene-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one

To determine the structures of two isomeric products, 2-phenacylidene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one (2) and 3-phenacylidene-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one (3) obtained by condensation of 2,3-diaminopyridine (1) with ethyl benzoylpyruvate [1–3], these compounds were hydrolyzed to give 2-methyl-4H-pyrido[2,3-b]pyrazin-3-one (4) and 3-methyl-1H-pyrido[2,3-b]pyrazin-2-one (5) , respectively [4,5]. Both hydrolysates 4 and 5 were hydrogenated to afford 2-methyl-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one (6) and 3-methyl-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one (7) . The latter compound was identical with an unequivocally synthesized compound providing proof for the structures of all these compounds.