Synthesis of 1,1,5,6-Tetramethyl- and 7-Isopropyl-1,1-dimethyl-1,2,3,4-tetrahydronaphthalene

1999 ◽  
Vol 64 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Ramchandra Bhimrao Mane ◽  
Abhijit Jaysingrao Kadam ◽  
Rajashree Sandeep Salunkhe
Keyword(s):  
Trifluoroacetic Acid ◽  
Polyphosphoric Acid ◽  
Titanium Tetrachloride ◽  
Grignard Reaction ◽  
Butanoic Acid ◽  
Methylmagnesium Iodide

4-(2,3-Dimethylphenyl)butanoic acid (4) was treated with excess of methyllithium to yield 5-(2,3-dimethylphenyl)-2-methylpentan-2-ol (6) which was cyclodehydrated using Dowex 50W-X8 resin, trifluoroacetic acid or polyphosphoric acid (PPA) to furnish 1,1,5,6-tetramethyl-1,2,3,4-tetrahydronaphthalene (1). The acid 4 was cyclized with PPA to furnish 5,6-dimethyl-3,4-dihydronaphthalen-1(2H)-one (5) which was converted into 1 by reaction with dimethylzinc and titanium tetrachloride. 4-(4-Isopropylphenyl)butanoic acid (7) on esterification followed by Grignard reaction with methylmagnesium iodide furnished 5-(4-isopropylphenyl)-2-methylpentan-2-ol (9), which was cyclodehydrated as above to yield 7-isopropyl-1,1-dimethyl-1,2,3,4-tetrahydronaphthalene (2).

scholarly journals Synthesis of 4-Aryl-3-ethoxycarbonyl-1-oxo-1,2,3,4-tetrahydronaphthalene: An Imporant Frame Work in Lignan Family

2012 ◽  
Vol 27 ◽  
pp. 86-93
Author(s):  
Ashok Kumar Singh
Keyword(s):  
Intramolecular Cyclization ◽  
Polyphosphoric Acid ◽  
Butanoic Acid ◽  
Butenoic Acid ◽  
Diethyl Succinate ◽  
Frame Work

4,4-diaryl-3-ethoxycarbonyl-3-butenoic acid (2a-d, Scheme 1) has been synthesized by Stobbe condensation of substituted benzophenones 1a-d with t-potassium butoxide and diethyl succinate. Compounds 2a-d on reduction with sodium amalgum furnished 4,4-diaryl-3-ethoxycarbonyl-3-butanoic acid 3a-d, which on intramolecular cyclization with polyphosphoric acid gave target compounds 4-aryl-3-ethoxycarbonyl-1-oxo--1,2,3,4-tetrahydronaphthalene 4a-d.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6666 J. Nepal Chem. Soc., Vol. 27, 2011 86-93 

Studies on intramolecular alkylation. X. The acid-catalysed reactions of 5,8-Dialkoxy-1,2,3,4-tetrahydronaphthyl diazomethyl ketones

1978 ◽  
Vol 31 (7) ◽  
pp. 1561 ◽  
Author(s):  
DW Johnson ◽  
LN Mander
Keyword(s):  
Trifluoroacetic Acid ◽  
Acid Treatment ◽  
Polyphosphoric Acid ◽  
Intramolecular Alkylation ◽  
Naphthoic Acid ◽  
Acid Catalysed Reactions ◽  
Diazomethyl Ketones

5,8-Dimethoxy-3,4-dihydronaphthalen-1(2H)-one was converted into diazomethyl 5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthyl ketone (10) which, when treated with trifluoroacetic acid at 0°, gave 5,8- dimethoxy-4,4a-dihydro-3,4a-ethanonaphthalen-2(3H)-one (13), but at -15° gave 8-methoxy-1,2,3,4-tetrahydro-3,4a-ethanonaphthalene- 5(4aH),10-dione (14). 6-Methoxy-3,4-dihydronaphtha-len-1(2H)-one reacted with m-chloroperoxybenzoic acid to give 4,5-dihydro-1-benzoxepin-2(3H)-one (15) which after hydrolysis, ethylation and polyphosphoric acid treatment gave 5-ethoxy-8-methoxy-3,4-dihydronaphthalen-1(2H)-one (17). This compound was transformed into 5-ethoxy-8-hydroxy-1,2,3,4-tetrahydro-2-naphthoic acid (19) and thence to the ethoxy analogue of (14).

Enolic Ortho Esters. VII Involvement of Magnesium Halides as Lewis Acids in the Reaction of Grignard Reagents with 1,6-Dideoxy- 1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5- enopyranose and its 6-Phenyl Derivative: a Correction

1998 ◽  
Vol 51 (8) ◽  
pp. 681 ◽  
Author(s):  
David J. Collins ◽  
Angus I. Hibberd ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Lewis Acids ◽  
Titanium Tetrachloride ◽  
Grignard Reagents ◽  
Ortho Ester ◽  
X Ray ◽  
Phenyl Derivative ◽  
Methylmagnesium Iodide ◽  
Ortho Esters ◽  
Phenylmagnesium Bromide

The known aldehyde methyl 2,3,4-tri-O-methyl-α-D-gluco-hexodialdo-1,5-pyranoside (9) was converted in eight steps into the 6-phenyl glucose-derived enolic ortho ester (Z)-1,6-dideoxy-1,1-ethylenedioxy- 2,3,4-tri-O-methyl-6-phenyl-D-xylo-hex-5-enopyranose (22), the geometry of which was established by a single-crystal X-ray study. Treatment of the 6-phenyl enolic ortho ester (22) with titanium tetrachloride at –78° effected clean rearrangement into (2R/S,4R,5R,6S)-3,3-ethylenedioxy-4,5,6-trimethoxy-2-phenylcyclohexanone (26). Reaction of (22) with methylmagnesium iodide gave (1R,2S,4R,5S,6S)-3,3-ethylenedioxy-4,5,6-trimethoxy-1-methyl-2-phenylcyclohexanol (24), the structure and stereochemistry of which were established by an X-ray study. Reaction of (22) with phenylmagnesium bromide gave (25), the 1-phenyl analogue of (24). The firmly established structure of (24) led to proof both chemically and by X-ray means that the product from reaction of 1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5-enopyranose (5) with methylmagnesium iodide has the hydroxy acetal structure (7) rather than the originally assigned hemiacetal structure (3).

scholarly journals SYNTHESIS AND REACTIONS OF 1-(4’-BROMOPHENACYL)-3-(4’-BROMO-PHENYL)-4,6-DIMETHOXYINDOLE

2010 ◽  
Vol 5 (2) ◽  
pp. 156-162
Author(s):  
Jumina Jumina
Keyword(s):  
Acetic Acid ◽  
Sodium Borohydride ◽  
Trifluoroacetic Acid ◽  
Boron Trifluoride ◽  
Polyphosphoric Acid ◽  
Glacial Acetic Acid ◽  
Boron Trifluoride Etherate ◽  
Phosphoryl Chloride ◽  
Acetyl Ester ◽  
Toluenesulfonic Acid

  1-Phenacyl-3-aryl-4,6-dimethoxyindoles 2b and 2c were obtained in good yields respectively through cyclization of N,N-diphenacylaniline 1b and 1c in trifluoroacetic acid. However, instead of giving pyrroloindole 3c, treatment of phenacylindole 2c with polyphosphoric acid afforded indolizine 5 in 42% yield. Phenacylindole 2c reacts with the Vilsmeier aroylation reagent consisted of a mixture of phosphoryl chloride and p-chloro-N,N-dimethylbenzamide to give 2-aroylindole 6 (32%) and pyrroloindole 7 (22%). When treated with sodium borohydride, phenacylindole 2c gave alcohol 8 in 83% yield. Nonetheless, treatment of alcohol 8 with either p-toluenesulfonic acid in glacial acetic acid or boron trifluoride etherate in benzene did not give the desired dihydropyrroloindole 12. Instead, the reactions afforded respectively acetyl ester 9 and indole 10 in 56% and 63% yield.   Keywords: phenacylindole, aroylindole, pyrroloindole, and indolizine.

Fluorinated tricyclic neuroleptics with prolonged action: 8-Alkyl derivatives of 3-fluoro-10-piperazino-10,11-dihydrodibenzo[b,f]thiepins

1984 ◽  
Vol 49 (11) ◽  
pp. 2638-2648 ◽  
Author(s):  
Jiří Jílek ◽  
Miroslav Rajšner ◽  
Jiřina Metyšová ◽  
Josef Pomykáček ◽  
Miroslav Protiva
Keyword(s):  
Polyphosphoric Acid ◽  
Titanium Tetrachloride ◽  
Prolonged Action ◽  
Substitution Reactions ◽  
Piperazine Derivatives ◽  
Alkyl Derivatives ◽  
Chloro Derivatives ◽  
Derivatives Of ◽  
By Products ◽  
Hydroxyethyl Piperazine

Reactions of (4-fluoro-2-iodophenyl)acetic or (2-bromo-4-fluorophenyl)acetic acid with 4-methylthiophenol, 4-ethylthiophenol and 4-isopropylthiophenol under various conditions afforded the acids IIIa-c which were cyclized with polyphosphoric acid to 8-alkyl-3-fluorodibenzo-[b,f]thiepin-10(11H)-ones IVa-c. The alcohols Va-c, which were obtained by reduction of the ketones with sodium borohydride, were transformed by treatment with hydrogen chloride to the chloro derivatives Via-c. Their substitution reactions with 1-methylpiperazine and 1-(2-hydroxyethyl)piperazine afforded the title compounds Ib, Ic and IIa. The corresponding 2-alkyl-7-fluorodibenzo[b,f]thiepins VIIa-c were obtained as by-products. Reaction of the ketone IVc with 1-methylpiperazine in the presence of titanium tetrachloride gave the enamine VIII. The piperazine derivatives prepared are very potent neuroleptic agents with regard to their acute activities. Important prolongation of the effects was found mainly with the isopropyl compounds Ic and VIII.

Synthesis of the radical scavenger 1,1,3,3-Tetramethylisoindolin-2-yloxyl

1983 ◽  
Vol 36 (2) ◽  
pp. 397 ◽  
Author(s):  
PG Griffiths ◽  
G Moad ◽  
E Rizzardo
Keyword(s):  
Free Radical ◽  
Small Proportion ◽  
Radical Scavenger ◽  
Grignard Reaction ◽  
Radical Trapping ◽  
Methylmagnesium Iodide ◽  
Trapping Agent

A versatile free-radical trapping agent, 1,1,3,3-tetramethylisoindolin-2-yloxyl, has been prepared from N-benzylphthalimide by reaction with 'methylmagnesium iodide' in refluxing toluene followed by hydrogenolysis and oxidation. The Grignard reaction gives 2-benzyl-1,1,3,3-tetramethylisoindoline along with a small proportion of an unexpected by-product, 2-benzyl-1-ethyl-1,3,3-trimethyliso-indoline.

Construction of the Side-Chain in 14β-Androst-5-ene Derivatives. Preparation of 14β-Pregnenolone

1994 ◽  
Vol 59 (12) ◽  
pp. 2691-2704 ◽  
Author(s):  
Ivan Černý ◽  
Miloš Buděšínský ◽  
Pavel Drašar ◽  
Vladimír Pouzar
Keyword(s):  
Nmr Spectra ◽  
Side Chain ◽  
Grignard Reaction ◽  
Diisobutylaluminum Hydride ◽  
Subsequent Oxidation ◽  
Hydride Reduction ◽  
Methylmagnesium Iodide ◽  
A Minor

Stepwise side-chain construction schemes leading to pregnane derivatives were tested in the 14β-androst-5-ene series. 6β-Methoxy-3α,5-cyclo-5α,14β-androstan-17-one (I) gave after methylenation and hydroboration the 17α-hydroxymethyl derivative III. Subsequent oxidation to the aldehyde VI, Grignard reaction with methylmagnesium iodide, and reoxidation led to the ketone VII and to the isomeric 17β-derivative VIII as a minor product. Final i-steroid cleavage of VII furnished the known 14β,17α-pregnenolone IX; the minor product VIII gave the 17β-isomer X. Alternatively, the ketone X was prepared from 6β-methoxy-3α,5-cyclo-5α,14β-androstan-17α-ol p-toluenesulfonate (XI) by cyanide substitution, diisobutylaluminum hydride reduction to the aldehyde XIV, and further as described for IX. The mass and NMR spectra of the four pregnenolone derivatives IX, X, XVIII, and XIX, isomeric in positions 14 and 17, were studied.

Enolic Ortho Esters. VI. A New 'Pyranose→Cyclohexane' Transformation via 1,6-Dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5-enopyranose

1996 ◽  
Vol 49 (3) ◽  
pp. 425 ◽  
Author(s):  
DG Bourke ◽  
DJ Collins ◽  
AI Hibberd ◽  
MD Mcleod
Keyword(s):  
Titanium Tetrachloride ◽  
Ortho Ester ◽  
Methylmagnesium Iodide ◽  
Swern Oxidation ◽  
Ortho Esters ◽  
Trimethylsilyl Trifluoromethanesulfonate ◽  
Hydrolysis Of

Hydrolysis of methyl 6-chloro-6-deoxy-2,3,4-tri-O-methyl-α-D-glucopyranoside (19b) and Swern oxidation of the resulting anomeric hemiacetals (20) gave 6-chloro-6-deoxy-2,3,4-tri-O-methyl-D-glucono-1,5-lactone (21), treatment of which with 1,2-bis( trimethylsilyloxy )ethane in the presence of trimethylsilyl trifluoromethanesulfonate gave 6-chloro-1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-glucopyranose (23a). Conversion of (23a) into the corresponding 6-iodo compound (23b) and treatment of this with 1,8-diazabicyclo[5.4.0]undec-7-ene afforded the enolic ortho ester 1,6-dideoxy-1,1-ethylenedioxy-2,3,4-tri-O-methyl-D-xylo-hex-5-enopyranose (26). Reaction of (26) with methylmagnesium iodide, or with titanium tetrachloride, gave (1R,6S,7R,8R,9S)-7,8,9-trimethoxy-6-methyl-2,5-dioxabicyclo[4.3.1]decan-1-ol (34), or (2S,3R,4R)-5,5-ethylenedioxy-2,3,4-trimethoxycyclohexanone (28), respectively.

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