Selective O-Methyloxime Formation From 6-Methoxy-2-[(1'-methyl-2',5'-dioxocyclopentyl)-methyl]-3,4-dihydronaphthalen-1(2H)-one

1994 ◽  
Vol 47 (4) ◽  
pp. 649 ◽  
Author(s):  
DJ Collins ◽  
GD Fallon ◽  
CE Skene
Keyword(s):  
Lithium Aluminium Hydride ◽  
X Ray ◽  
X Ray Crystallography ◽  
Lithium Aluminium ◽  
Major Isomer ◽  
Toluenesulfonic Acid ◽  
Ester Formation ◽  
Diastereomeric Mixture ◽  
A Minor

Reaction of 6-methoxy-2-[(1′-methyl-2′,5′-dioxocyclopentyl)methyl]-3,4-dihydronaphthalen-1(2H)-one (4a) with 1 or 2 moles of O- methylhydroxylamine hydrochloride in pyridine gave (1′SR,2RS)-6-methoxy-2-[(1′-methyl-2′,5′-dioxocyclopentyl)methyl]-3,4-dihydronaphthalen-1(2H)-one (E)-2′-O-methyloxime (5a), or the corresponding 2′,5′-bis(O-methyloxime ) (6), respectively. A minor product from the formation of the bis (O- methyloxime ) (6) was the (Z) isomer (5b) of the mono(O- methyloxime ) (5a); the structure and stereochemistry of (5a) and (5b) were established by X-ray crystallography. Reduction of the keto bis (O-methyloxime ) (6) with 0.25 mole of lithium aluminium hydride gave a diastereomeric mixture of the corresponding alcohols (7a), of which the major isomer was characterized by ester formation. The bis (O-methyloxime ) (6) could be hydrolysed to the parent triketone (4a), but it resisted deprotection with cetyltrimethylammonium permanganate. Reaction of the triketone (4a) with 1 mole of 4-anisidine in the presence of 4-toluenesulfonic acid resulted in retro Michael cleavage with formation of 3-(4′-methoxyphenyl)amino-2-methylcyclopent-2-en-1-one (1).

Some oxidation products of lycoctonine revisited

2006 ◽  
Vol 84 (9) ◽  
pp. 1167-1173 ◽  
Author(s):  
Doaa Abdelrahman ◽  
Michael Benn ◽  
Ryan Hellyer ◽  
Masood Parvez ◽  
Oliver E Edwards
Keyword(s):  
Oxidation Product ◽  
Chromic Acid ◽  
Oxidation Products ◽  
Acid Oxidation ◽  
Lithium Aluminium Hydride ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chromic Acid Oxidation ◽  
Lithium Aluminium ◽  
Norditerpenoid Alkaloid

The structure of a chromic acid oxidation product of the norditerpenoid alkaloid lycoctonine (1) was established as hydroxylycoctonal (3) by spectrometric analyses and X-ray crystallography of its reduction product, hydroxylycoctonine (5); the structure of lycoxonine, a chromic acid oxidation product of the lactam, lycoctonam (7), was similarly confirmed as N-ethyl-4,7,8-trihydroxy-1α,6β,14α,16β-tetramethoxy-19-oxoaconitane (8). Reduction of lycoxonine with lithium aluminium hydride gave the 1,14-di-O-methyl ether (12) of the bisnorditerpenoid alkaloid delbine (9).Key words: norditerpenoid, bisnorditerpenoid, alkaloids, lycoctonine, lycoctonam, hydroxylycoctonal, lycoxonine. 1,14-di-O-methyldelbine, semisynthesis.

The Chemistry of Laurenene. VI. An Investigation of the Widely Differing Reactivity of a Pair of Epimeric Keto Esters

1987 ◽  
Vol 40 (9) ◽  
pp. 1591
Author(s):  
LR Hanton ◽  
SD Lorimer ◽  
RT Weavers
Keyword(s):  
Lithium Aluminium Hydride ◽  
Two Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
Keto Esters ◽  
Lithium Aluminium

X-ray crystallography and two-dimensional n.m.r. techniques have been used to establish the conformations of the epimeric keto esters (1) and (3), derived from cleavage of ring A of lauren-1-ene (2). This information has been used to rationalize the disparate reactivity of the keto functions of (1) and (3) in acid-catalysed carbocation rearrangements and with lithium aluminium hydride. The structures of two new rearranged ethers derived from (1) are also discussed.

Aminodideoxy sugars. Methyl 3-acetamido-2,3-dideoxy-α-D-arabino-hexopyranoside and methyl 2-acetamido-2,3-dideoxy-α-D-ribo-hexopyranoside

1969 ◽  
Vol 47 (15) ◽  
pp. 2747-2750 ◽  
Author(s):  
Alex Rosenthal ◽  
P. Catsoulacos
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Minor Amount ◽  
Yield Reduction ◽  
Aqueous Acetic Acid ◽  
Lithium Aluminium Hydride ◽  
Parallel Reaction ◽  
Lithium Aluminium ◽  
Methyl Sulfoxide ◽  
A Minor

Oxidation of methyl 4,6-O-benzylidene-3-deoxy-α-D-arabino-hexopyranoside (2) with methyl sulfoxide and acetic anhydride yielded methyl 4,6-O-benzylidene-3-deoxy-α-D-erythro-hexopyranosid-2-ulose (3) in an 80% yield. Reduction of the oximino derivative of 3 with lithium aluminium hydride in tetrahydrofuran or with diborane afforded, after acetylation, methyl 2-acetamido-4,6-O-benzylidene-2,3-dideoxy-α-D-ribo-hexopyranoside (6) in a 44% yield. The latter was also debenzylidenated with aqueous acetic acid. In a parallel reaction, methyl 4,6-O-benzylidene-2,3-dideoxy-3-oximino-α-D-erythro-hexopyranoside yielded mainly methyl 3-acetamido-4,6-O-benzylidene-2,3-dideoxy-α-D-arabino- (and a minor amount of the ribo-epimer)-hexopyranoside.

Tricyclic neuroleptics: Synthesis of metabolites of isofloxythepin and some related compounds

1990 ◽  
Vol 55 (9) ◽  
pp. 2282-2303 ◽  
Author(s):  
Karel Šindelář ◽  
Jiří Jílek ◽  
Josef Pomykáček ◽  
Vladimír Valenta ◽  
Marta Hrubantová ◽  
...  
Keyword(s):  
Formic Acid ◽  
Substitution Reaction ◽  
Lithium Aluminium Hydride ◽  
Enol Ether ◽  
Basic Product ◽  
Lithium Aluminium ◽  
Toluenesulfonic Acid ◽  
Neuroleptic Agent ◽  
Related Compounds ◽  
By Products

The isofloxythepin (I) metabolite IV was synthesized via the acids IX and XI and the esters X and XII. The enamine VIII was prepared from 3-fluoro-8-(2-propyl)dibenzo[b,f]thiepin-10(11H)-one by two methods and was reduced to I. Cloflumide (II) was obtained by reaction of 2,10-dichloro-7-fluoro-10,11-dihydrodibenzo[b,f]thiepin with 3-(1-piperazinyl)propionamide and was oxidized to the sulfoxide XVI. The unsaturated analogue XVII of clopithepin (III) was prepared from 2-chlorodibenzo[b,f]thiepin-10(11H)-one by reaction with 2-bromoethanol in the presence of 4-toluenesulfonic acid in boiling benzene and by the following substitution reaction with 2-(1-piperazinyl)ethanol. An improved synthesis of 6-methyldibenzo[b,f]thiepin-10(11H)-one (XIX) was elaborated. The acid XXVII was synthesized and cyclized with polyphosphate ester. A mixture of compounds was formed from which the ketone XXXVI was isolated and processed by reaction with formamide and formic acid at 200 °C. One of the products was characterized as the formamide XXXIII and was reduced with lithium aluminium hydride to a basic product supposed to be XXXIV. A series of by-products was isolated and characterized. The enamine VIII (V⁄FB-17 156) was found to be a strong neuroleptic agent, similar to isofloxythepin (I). The enol ether XVII (V⁄FB-17 733) was characterized as a mild, practically noncataleptic neuroleptic agent.

Synthesis of 6-Methoxy-2-methyl-2-[(1'-methyl-2',5'-dioxocyclopentyl)methyl]-3,4-dihydro-naphthalen-1(2H)-one: Its Novel Base-Catalyzed Rearrangement to a Hydrophenanthrene Keto Acid

1994 ◽  
Vol 47 (4) ◽  
pp. 623 ◽  
Author(s):  
DJ Collins ◽  
GD Fallon ◽  
CE Skene
Keyword(s):  
Acetic Acid ◽  
Ethylene Glycol ◽  
Acid Hydrolysis ◽  
Keto Acid ◽  
X Ray ◽  
X Ray Crystallography ◽  
Aldol Cyclization ◽  
Diastereomeric Mixture ◽  
Rearrangement Reaction ◽  
Reactions With Nucleophiles

Reaction of 2-dimethylaminomethyl-6-methoxy-3,4-dihydronaphthalen-1(2H)-one (7) with 2-methylcyclopentane-1,3-dione gave 64% of 6-methoxy-2-[(1′-methyl-2′,5′-dioxocyclopentyl)-methyl]-3,4-dihydronaphthalen-1(2H)-one(6a), which with 1 equiv. of ethylene glycol in refluxing benzene in the presence of 4-toluenesulfonic acid yielded a diastereomeric mixture of the 2′,2̶-ethylenedioxy derivatives (13a,b); the major diastereomer (13a) was shown to have 1′SR,2RS stereochemistry by X-ray crystallography. With an excess of ethylene glycol and prolonged reflux the triketone (6a) underwent aldol cyclization/acetalization to give 9,9,12,12-bis(ethylenedioxy)-3-methoxy-8-methyl-5,6,8,9,10,11-hexahydro-8,11-methano-7H-cyclohepta[a]naphthalene (19). With pyridinium 4-toluenesulfonate as catalyst, aldol cyclization was avoided, and the tri-ketone (6a) afforded 2-[(2′,2′,5′,5′-bis(ethylenedioxy)-1′-methylcyclopentyl)methyl]-6-methoxy-3,4-dihydronaphthalen-1(2H)-one (15). The triketone (6a) and its monoacetal (13a,b) were susceptible to reverse Michael cleavage in reactions with nucleophiles under either acidic or basic conditions. Methylation of the keto diacetal (15), followed by acid hydrolysis, gave 6-methoxy-2-methyl-2-[(1′-methyl-2′,5′-dioxocyclopentyl)methyl]-3,4-dihydronaphthalen-1(2H)-one (6b); 2-[(2′,2′-ethylenedioxy-1′-methyl-5′-oxocyclopentyl)methyl]-6-methoxy-2-methyl-3,4-dihydronaphtha - len-1(2H)-one (32), resulting from incomplete hydrolysis, was shown to have 1′RS,2RS stereochemistry by X-ray crystallography. The triketone (6b) underwent a novel base-catalysed rearrangement reaction to give 7-methoxy-2ξ,10a-dimethyl-3-oxo-1,2,3,9,10,10a-hexahydrophenanthrene-4-acetic acid (33) which readily afforded the corresponding enol lactone (35).

Selective chemistry of tripentaerythritol — Synthesis of acetals and their derivatives

2006 ◽  
Vol 84 (4) ◽  
pp. 516-521 ◽  
Author(s):  
Hussein Al-Mughaid ◽  
T Bruce Grindley
Keyword(s):  
Lewis Acid ◽  
Chemical Shifts ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
X Ray Crystallography ◽  
Catalysed Reaction ◽  
Toluenesulfonic Acid ◽  
C Nmr

Tripentaerythritol was converted efficiently into 2′,2′′:6′,6′′:10′,10′′-tri-O-cyclohexylidene-2,2,6,6,10,10-hexakis(hydroxymethyl)-4,8-dioxa-1,11-undecandiol (4) by the toluenesulfonic acid catalysed reaction with cyclohexanone in a mixture of N,N-dimethylformamide and benzene. Reaction of tripentaerythritol with benzaldehyde under similar conditions gave an easily separated mixture of the four possible stereoisomers. Structures of these stereoisomers were assigned based on 1H and 13C NMR chemical shifts using trends previously observed for the dibenzylidene acetals of dipentaerythritol, whose structures had been established unambiguously by X-ray crystallography. It was found that reduction of the mixture of benzylidene acetals to 2,6,10-tris(benzyloxymethyl)-4,8-dioxa-1,11-undecanediol could be accomplished using triethylsilane with ethylaluminium dichloride as the Lewis acid after a number of commonly used conditions for this transformation failed.Key words: pentaerythritol, tripentaerythritol, dipentaerythritol, acetals, benzylidene acetals, reduction.

The synthesis, separation, and crystal and molecular structures of the three bisphenols, an ethanol solvate of one of them, and of a minor by-product, 6,6′,7,7′-tetrachloro-8,8′-methylenebis(4H-benzo-1,3-dioxin), prepared by condensation of formaldehyde with 3,4-dichlorophenol

1989 ◽  
Vol 67 (5) ◽  
pp. 779-785 ◽  
Author(s):  
George Ferguson ◽  
Robert McCrindle ◽  
Alan James McAlees
Keyword(s):  
Molecular Structures ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ethanol Solvate ◽  
Crystallographic Symmetry ◽  
Molar Equivalent ◽  
Acid Catalyzed ◽  
A Minor ◽  
Hydrogen Bonded

Samples of all three of the expected bisphenols, 4,4′,5,5′-tetrachloro-2,2′-methylenebisphenol (1) and the 3,4,4′,5′-(2) and 3,3′,4,4′-tetrachloro (3) isomers, and of a minor by-product, 5,5′,6,6′-tetrachloro-8,8′-methylenebis(4H-benzo-1,3-dioxin) (4), have been isolated from the mixture formed by acid-catalyzed condensation of 3,4-dichlorophenol with one half of a molar equivalent of formaldehyde. In addition, the structures and solid state conformations of all four compounds, and of an ethanol solvate of 1, have been revealed by X-ray crystallographic studies. The three bisphenols (1, 2, 3) all crystallize in space group [Formula: see text], as centrosymmetric hydrogen-bonded dimers, while the solvate, 1•EtOH, although it also belongs to space group [Formula: see text], forms relatively open infinite bands of hydrogen-bonded molecules. Crystals of 4 belong to space group Fdd2 and the molecules have twofold crystallographic symmetry. Keywords: X-ray crystallography, bisphenols, tetrachloro-2,2′-methylenebisphenols, tetrachloro-8,8′-methylenebis(4H-benzo-1,3-dioxin).

Oxidation-Induced Acyl Group Transfer from Hydroquinone Esters to Nucleophiles

1998 ◽  
Vol 53 (7) ◽  
pp. 765-773 ◽  
Author(s):  
Gerald Reischl ◽  
Medhat El-Mobayed ◽  
Rudolf Beißwenger ◽  
Klaus Regier ◽  
Cäcilia Maichle-Mössmer ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Amino Acids ◽  
Chemical Oxidation ◽  
Acyl Transfer ◽  
X Ray ◽  
Group Transfer ◽  
Tert Butyl ◽  
X Ray Crystallography ◽  
Toluenesulfonic Acid ◽  
Mediated Oxidation

Bivalent oxidation of 3,5-di-tert-butyl-hydroquinone monoesters leads to phenoxenium ions, which can transfer an acyl group to nucleophiles. Based on this principle, dipeptides, glyco-amino acids and N-sulfonyl-amino acids were synthesized from hydroquinone esters of amino acids and p-toluenesulfonic acid. For this reaction, direct anodic and indirect mediated oxidation, as well as chemical oxidation with NBS or trisarylammoniumyl salts, was used. The mechanism of the acyl transfer is discussed in terms of a direct and/or a mediated process. A spirocyclic key intermediate was isolated and its molecular structure determined by X-ray crystallography.

The structure and function of oestrogens. VIII. Synthesis of 5,5, 10b-Trimethyl-cis-4b,5,6,10b,11,12-hexahydrochrysene-2,8-diol from 6-Methoxy-3,4-dihydronaphthalen-1(2H)-one

1984 ◽  
Vol 37 (11) ◽  
pp. 2279 ◽  
Author(s):  
DJ Collins ◽  
JD Cullen ◽  
GD Fallon ◽  
BM Gatehouse
Keyword(s):  
Methanesulfonic Acid ◽  
Enol Ether ◽  
X Ray ◽  
X Ray Crystallography ◽  
Hydride Reduction ◽  
Lithium Aluminium ◽  
Ring Junction ◽  
Clemmensen Reduction ◽  
And Function ◽  
Zinc Iodide

Treatment of 2-hydroxymethylene-6-methoxy-3,4-dihydronaphthalen-1(2H)-one (13a) with p-meth-oxyphenyllead triacetate afforded 93% of 2-formyl-6-methoxy-2-(p-methoxyphenyl)-3,4-dihydro- naphthalen-1(2H)-one (14a) which upon deformylation and methylation gave 60% of 6-methoxy- 2-(p-methoxyphenyl)-2-methyl-3,4-dihydronaphthalen-1(2H)-one (17). An alternative route to the α α'-disubstituted ketone (17) by way of 6-methoxy-2-methyl-3,4-dihydronaphthalen-1(2H)-one (15) and 2-chloro-6-methoxy-2-methyl-3,4-dihydronaphthalen-1(2H)-one (16) was less efficient. Lithium aluminium hydride reduction of the ketone (17) followed by acetylation yielded 80% of 1 ξ acetoxy- 6-methoxy-2-(p-methoxyphenyl)-2-methyl-1,2,3,4-tetrahydronaphthalene (23), treatment of which with the trimethylsilyl enol ether of ethyl 2-methylpropanoate in the presence of zinc iodide afforded 71% of ethyl (1SR,2RS)-2-methyl-2-[6'-methoxy-2'-(p-methoxyphenyl)-2'-methyl-1',2 ',3',4'-tetrahydronaphthalen-yl'ξ-yl]propanoate (26a). Treatment of the ester (26a) or the corresponding acid (26b) with methanesulfonic acid yielded 68 or 82% respectively, of 2*-dimethoxy-5,5,10b-trimethyl- cis-4b,10b,11,12-tetrahydrochrysen-6(5H)-one (27a); Clemmensen reduction of this followed by demethylation with hydrobromicacidin aceticacid gave 49% of cis-5,5,10b-trimethyl-4b,5,6,10b,11,12- hexahydrochrysene-2,8-diol (7a). The sterochemistry of the ring junction in compound (7a) was established by X-ray crystallography of the corresponding dimethyl ether (27b).

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