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 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).

Systhesis, Characterization and Spectroscopic Properties of (2E,6E)-2,6-Bis(2,3,4-tri-methoxy-benzylidene)cyclohexanone

2011 ◽  
Vol 396-398 ◽  
pp. 2338-2341
Author(s):  
Xing Chuan Wei ◽  
Zhi Li Liu ◽  
Kun Zhang ◽  
Zhi Yun Du ◽  
Xi Zheng
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Spectroscopic Properties ◽  
Spectral Studies ◽  
Double Bonds ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography

In this paper, (2E,6E)-2,6-Bis(2,3,4-tri-methoxy -benzylidene)cyclohexanone (omitted as tmbcho) (1) was obtained by the reaction of acetic acid, tetrahydrofuran, cyclohexanone and 2,3,4-tri-methoxy-benzaldehyde. Three non-classic hydrogen bonds were observed in the compound. X-ray crystallography shows that the crystal structure is stabilized by intermolecular C-H•••π interactions and it contains plenty of conjugated double bonds. The title compound was characterized by UV-vis and fluorescent spectral studies.

Structure Elucidation of 2-Amino-5-phenyl-2-oxazolin-4-one (Pemoline) and X-Ray Structure of its Hydrolysis Product 5-Phenyl-oxazolidine-2,4- dione

2005 ◽  
Vol 60 (8) ◽  
pp. 853-857 ◽  
Author(s):  
Piotr Kuś ◽  
Peter G. Jones ◽  
Rafał Celiński
Keyword(s):  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Acid Hydrolysis ◽  
Single Crystals ◽  
Structure Elucidation ◽  
Hydrolysis Product ◽  
Spectroscopic Properties ◽  
Aqueous Acetic Acid ◽  
X Ray ◽  
Independent Molecules

In this study we compare spectroscopic properties of pemoline (2-amino-5-phenyl-2-oxazolin- 4-one) and its acid hydrolysis product 5-phenyl-oxazolidine-2,4-dione. Crystallization of pemoline from aqueous acetic acid gave single crystals of compound 2, the structure of which was determined by X-ray studies. All four crystallographically independent molecules form dimers linked by N-H···O = C hydrogen bonds.

Effects of solvents on the crystal structure of cross-linked lysozyme crystals

2018 ◽  
Vol 32 (19) ◽  
pp. 1840041
Author(s):  
Yohei Yamada ◽  
Shota Toyama ◽  
Tomoki Yabutani
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Dimethyl Sulfoxide ◽  
Optical Microscopy ◽  
Immersion Test ◽  
X Ray ◽  
Lattice Constants ◽  
X Ray Crystallography ◽  
Lysozyme Crystals

The effects of solvents on the structural stability of cross-linked lysozyme crystals were investigated by an immersion test using alkaline (0.1 M ammonia [NH3] and 0.1 M sodium hydroxide [NaOH]), acidic (0.1 M acetic acid [CH3COOH] and 0.1 M hydrochloric acid [HCl]) and organic (50% [v/v] and undiluted ethanol, acetone, 2-propanol and dimethyl sulfoxide [DMSO]) solvents. The morphology and lattice constants were monitored by optical microscopy and X-ray crystallography. The cross-linked crystals exhibited good stability against NH3, CH3COOH, HCl, ethanol, acetone and 2-propanol. However, samples preserved in DMSO and NaOH were severely degraded.

Direct Synthesis of 6H-Chromeno[3,4-b]quinolin-6-ol Derivatives from Substituted 3-Nitro-2H-chromenes and 2-Nitrobenzaldehydes Mediated by Fe/AcOH System

Synthesis ◽  
2017 ◽  
Vol 50 (06) ◽  
pp. 1350-1358 ◽  
Author(s):  
Cunde Wang ◽  
Xushun Qing ◽  
Ting Wang ◽  
Chenlu Dai ◽  
Zhenjie Su
Keyword(s):  
Acetic Acid ◽  
Nucleophilic Addition ◽  
Aldol Condensation ◽  
Direct Synthesis ◽  
Reductive Cyclization ◽  
Quinoline Derivatives ◽  
Acid System ◽  
X Ray ◽  
X Ray Crystallography ◽  
Sequential Reduction

An efficient iron/acetic acid system-mediated reductive cyclization reaction of substituted 2-aryl-3-nitro-2H-chromenes with substituted 2-nitrobenzaldehydes for the synthesis of 6-aryl-6H-chromeno[3,4-b]quinolines was developed. This reaction involves the sequential reduction, hydrolysis, aldol condensation, intramolecular addition, and the nucleophilic addition of substituted 2-aryl-3-nitro-2H-chromenes with substituted 2-nitrobenzaldehydes to give the corresponding 6H-chromeno[3,4-b]quinolines. This transformation provides a straightforward synthetic protocol for constructing substituted 6H-chromeno[3,4-b]quinoline derivatives. The structures of three typical products were confirmed by X-ray crystallography.

Fused Supracyclopentadienyl Ligand Precursors. Synthesis, Structure, and Some Reactions of 1,3-Diphenylcyclopenta[l]phenanthrene-2-one, 1,2,3-Triphenylcyclopenta[l]phenanthrene-2-ol, 1-Chloro-1,2,3-triphenylcyclopenta[l]phenanthrene, 1-Bromo-1,2,3-triphenylcyclopenta[l]phenanthrene, and 1,2,3-Triphenyl-1H-cyclopenta[l]phenanthrene

2006 ◽  
Vol 59 (2) ◽  
pp. 135 ◽  
Author(s):  
Glen D. Dennis ◽  
David Edwards-Davis ◽  
Leslie D. Field ◽  
Anthony F. Masters ◽  
Thomas Maschmeyer ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Good Yield ◽  
Photochemical Reaction ◽  
Subsequent Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Independent Synthesis ◽  
Ligand Precursors

The photochemical reaction of 1,3-diphenylcyclopenta[l]phenanthrene-2-one 5 (phencyclone) with oxygen in acetone leads to the formation of 1,2,3-trihydro-1,2,3-triphenylcyclo-penta[l]phenanthrene 7 (9,10-dibenzoylphenanthrene) along with a trace of the lactone 1,4-diphenylcyclo-3-pyran[l]phenanthrene-2-one 8. An independent synthesis of 8 was achieved by the reaction of 5 with FeCl3 in CHCl3. The treatment of 5 with phenyllithium yields 1,2,3-triphenylcyclopenta[l]phenanthrene-2-ol 9-OH in good yield. Subsequent reaction of 9-OH with SOCl2 or SOBr2 in pyridine leads to the formation of the halo-analogues 1-chloro-1,2,3-triphenylcyclopenta[l]phenanthrene 9-Cl and 1-bromo-1,2,3-triphenylcyclopenta[l]phenanthrene 9-Br, respectively. Treatment of 9-OH with HBr in acetic acid affords the rearranged product 1,1,3-triphenylcyclopenta[l]phenanthrene-2-one 10 with a trace of 9-Br. Treatment of 9-Cl or 9-Br with zinc in acetic acid affords 1,2,3-tri-phenyl-1H-cyclopenta[l]phenanthrene 9-H. 9,10-Phenanthrenediylbis(phenyl)methanone 7 is formed in good yield upon treatment of 9-OH with HI in acetic acid followed by heating with H2PO4. Compounds 7, 8, 9-Cl, 9-Br, and 10 have been structurally characterized using X-ray crystallography.

Different solvents yield alternative crystal forms through aromatic, halogen bonding and hydrogen bonding competition

CrystEngComm ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 877-888 ◽  
Author(s):  
Solhe F. Alshahateet ◽  
Mohan M. Bhadbhade ◽  
Roger Bishop ◽  
Marcia L. Scudder
Keyword(s):  
Hydrogen Bonding ◽  
Acetic Acid ◽  
Halogen Bonding ◽  
Crystal Forms ◽  
X Ray ◽  
X Ray Crystallography ◽  
Protic Solvents

X-ray crystallography shows that entirely different structures are produced when the dichlorodiquinoline derivative is crystallised from aprotic dimethylformamide or from protic solvents like methanol or acetic acid, demonstrating the importance of solvent choice in yielding alternative crystal forms.

scholarly journals Unexpected Formation of Hexasubstituted Arenes Through a Twofold Palladium-Mediated Ligand Arylation

2019 ◽  
Author(s):  
Corin Wagen ◽  
Bryan T. Ingoglia ◽  
Stephen L. Buchwald
Keyword(s):  
Unexpected Formation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Rearrangement Reaction ◽  
Supported Pd

<div> <p>A rearrangement reaction of biarylphosphine-supported Pd(II) complexes was employed to synthesize 1,3,5-triaryl 2,4,6-triisopropylbenzene compounds, a class of molecules that has not previously been reported. The strain of the central hexasubstituted ring was investigated via X-ray crystallography.</p> </div> <br>

The Chemistry of Laurenene. IX. Crystal-Structure of a Ring A Seco Keto Acid

1988 ◽  
Vol 41 (10) ◽  
pp. 1571 ◽  
Author(s):  
AR Hayman ◽  
J Simpson ◽  
RT Weavers
Keyword(s):  
Crystal Structure ◽  
Crystal Lattice ◽  
Keto Acid ◽  
X Ray ◽  
X Ray Crystallography

X-Ray crystallography has shown that the laurenene derived keto acid, 1-oxo-1,2-secolaurenan-2-oic acid (2a), exists in two distinct twist conformations in the crystal lattice. Comparison with data previously reported for a derivative of the 15-epimer (1b) provides an explanation for the extraordinary difference in reactivity between ring A seco laurenane derivatives with the 15α- and 15β-methyl stereochemistries.

Synthesis, Characterization and Reactivity of a Diorganotin Thiocarboxylate: Dimethyl(thioacetato)-tin(IV) Chloride and its Reactions with Nucleophiles Exhibiting Desulfurization

2009 ◽  
Vol 64 (1) ◽  
pp. 116-122 ◽  
Author(s):  
Neetu Singh ◽  
Subrato Bhattacharya ◽  
Heinrich Nöth ◽  
Peter Mayer
Keyword(s):  
Ftir Spectroscopy ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Thioacetic Acid ◽  
Reaction Conditions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Tin Chloride ◽  
Reactions With Nucleophiles

Dimethyl(thioacetato)tin chloride (1) was synthesized by the reaction of dimethyltin dichloride with thioacetic acid in the presence of triethylamine. Compound 1 was subjected to hydrolysis under different reaction conditions in order to obtain sulfido/hydrosulfidotin compounds. Except for one case where the product was hexamethyl-1,3,5-trithia-2,4,6-tristannacyclohexane, (Me2SnS)3 (4), all other reactions led to desulfurization, and the products obtained were organostannoxane compounds, dinuclear tetramethyl-oxo-dichloroditin, {Me2SnCl2.Me2SnO}2 (2), and tetraacetatodioxotetra( dimethyltin), (Me2Sn)4O2(O2CMe)4 (3). These complexes have been characterized by 1H, 13C, 119Sn NMR and FTIR spectroscopy, and compounds 2 - 4 also by X-ray crystallography. Density functional calculations were performed to explain the structure and reactivity of the compounds.

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