scholarly journals STUDIES IN THE CYCLIZATION OF THE PRODUCTS OF STOBBE CONDENSATION WITH PROPIOPHENONE

1965 ◽  
Vol 43 (8) ◽  
pp. 2408-2414 ◽  
Author(s):  
A. M. El-Abbady ◽  
S. H. Doss
Keyword(s):  
Carboxylic Acid ◽  
Acetic Anhydride ◽  
Sodium Acetate ◽  
Catalytic Reduction ◽  
Stannic Chloride ◽  
Unsaturated Ester ◽  
Isomeric Mixture ◽  
Keto Ester ◽  
Diethyl Succinate ◽  
Naphthoic Acid

The isomeric mixture of the half-esters resulting from the Stobbe condensation of propiophenone with diethyl succinate is cyclized with stannic chloride as well as with sodium acetate in acetic anhydride. Cyclization of the ethyl half-ester chlorides with stannic chloride gives the keto-ester "4-carbethoxy-2-methyl-3-phenylcyclopent-2-enone." This on acid hydrolysis and decarboxylation yields 2-methyl-3-phenylcyclopent-2-enone, from which 2-methyl-3-phenylcyclopentanone is prepared by catalytic reduction. The keto-ester on Clemmensen reduction gives the corresponding unsaturated ester from which 3-methyl-2-phenylcyclopentane-1-carboxylic acid is obtained by catalytic hydrogenation and hydrolysis. 2-Methyl-3-phenylcyclopentanone and 3-methyl-2-phenylcyclopentane-1-carboxylic acid are of interest as intermediates for analogues of steroid hormones. From the latter 3-methyl-2-phenylcyclopentyl hydroxymethyl ketone and its acetate are prepared.Cyclization of the isomeric mixture of the ethyl half-esters with sodium acetate in acetic anhydride gives methyl 4-acetoxy-1-ethyl-2-naphthoate which is converted into 1-ethyl-4-methoxy-2-naphthoic acid.

Pulse polarographic study of the behaviour of some o,o'-dihydroxyazo-compounds

1989 ◽  
Vol 54 (5) ◽  
pp. 1219-1226 ◽  
Author(s):  
Enric Casassas ◽  
Miquel Esteban ◽  
Santiago Alier
Keyword(s):  
Carboxylic Acid ◽  
Reaction Mechanisms ◽  
Sulphonic Acid ◽  
Base Catalysis ◽  
Polarographic Study ◽  
Acid Base ◽  
Eriochrome Black T ◽  
Naphthoic Acid ◽  
Calcon Carboxylic Acid

The reduction of several o,o'-dihydroxyazo-compounds is studied by means of pulse polarographic techniques (DPP, NPP and RPP). The compounds studied are the following: 2-(2'-hydroxyphenylazo)-phenol (o,o'-dihydroxyazobenzene), 1-(2'-hydroxy-1'-naphthylazo)-2-naphthol-4-sulphonic acid (calcon or Eriochrome Blue Black R), 1-(2'-hydroxy-4'-sulpho-1'-naphthylazo)-2-hydroxy-3-naphthoic acid (calcon carboxylic acid), and 1-(1'-hydroxy-2'-naphthylazo)-6-nitro-2-naphthol-4-sulphonic acid (Eriochrome Black T). Correlations between Ip and Epand experimental variables (pH, T, conc.) and instrumental parameters (dropping time, t, and pulse magnitude, ΔE) are established. Reaction mechanisms formerly proposed are discussed on the basis of the new obtained results, and the ranges are defined where adsorption and/or acid-base catalysis are operative.

Synthesis of peptides containing 1,2,3,4-tetrahydroquinoline-2-carboxylic acid. Part 3. Cyclization of dipeptides and amides with acetic anhydride

1979 ◽  
Vol 16 (8) ◽  
pp. 1589-1597 ◽  
Author(s):  
Giampiero Pagani Zecchini ◽  
Mario Paglialunga Paradisi
Keyword(s):  
Carboxylic Acid ◽  
Acetic Anhydride

A Simple Synthesis of 4-Substituted 2-(3-Hydroxy-2-oxo-1-phenethylpropylcarbamoyl) pyrrolidine-1-carboxylic Acid Benzyl Esters as Novel Cysteine Protease Inhibitors

2008 ◽  
Vol 63 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Seikwan Oh ◽  
Jae-Chul Jung ◽  
Mitchell A. Avery
Keyword(s):  
Carboxylic Acid ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Good Yield ◽  
Sodium Acetate ◽  
Simple Synthesis ◽  
Insertion Reaction ◽  
Cysteine Protease Inhibitors ◽  
Convenient Synthesis ◽  
Benzyl Esters

A convenient synthesis of 4-substituted 2-(3-hydroxy-2-oxo-1-phenethylpropylcarbamoyl)pyrrolidine- 1-carboxylic acid benzyl esters 17 and 18 as new cysteine protease inhibitors is described. The synthetic key strategies involve the diazocarbonyl insertion reaction of N-Boc-L-homophenylalanine (1) by diazomethane, acetylation of the bromoketone 2 with sodium acetate, and condensation of acids 12, 14 with (3S)-3-amino-2-oxo-5-phenyl-pentyl acetate monohydrochloride (4) in good yield

Synthetic application of cyclobutanes V. α-Carbalkoxymethylation of α, β-unsaturated ketones

1977 ◽  
Vol 55 (5) ◽  
pp. 822-830 ◽  
Author(s):  
Hsing-Jang Liu ◽  
Patrick Chi-Lin Yao
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Potassium Carbonate ◽  
Alkyl Iodide ◽  
Keto Ester ◽  
Unsaturated Ketones ◽  
Synthetic Application ◽  
Hydrolysis Of ◽  
Villiger Oxidation

Two general methods for α-carbalkoxymethylation of both enolizable and nonenolizable (towards the γ-position) α,β-unsaturated ketones have been developed. Method A involves three synthetic steps: photocycloaddition of the starting enone to 1,1-dimethoxyethylene, hydrolysis–oxidation of the adduct with acetic acid and 30% hydrogen peroxide, and O-alkylation of the resulting mixture of lactone and acid using anhydrous potassium carbonate and an alkyl iodide, e.g., 13 → 17 → 21 + 22 → 23. Method B differs from method A in the means of securing the required cyclobutanone intermediate. Thus, photocycloaddition of 13 to vinyl acetate followed by hydrolysis of the adduct gave two epimeric keto alcohols 39 whose oxidation with dimethyl sulfoxide and acetic anhydride afforded diketone 40. Baeyer–Villiger oxidation of 40 followed by methylation of the products 21 and 22 completed the overall α-carbomethoxymethylation process to give keto ester 23.

Tracer Studies with Radioactive Carbon. The Exchange between Acetic Anhydride and Sodium Acetate

1942 ◽  
Vol 64 (12) ◽  
pp. 3050-3050 ◽  
Author(s):  
S. Ruben ◽  
M. B. Allen ◽  
P. Nahinsky
Keyword(s):  
Acetic Anhydride ◽  
Sodium Acetate ◽  
Tracer Studies ◽  
Radioactive Carbon

Analysis of 2-amino-2-deoxyhexoses by gas–liquid partition chromatography

1968 ◽  
Vol 46 (9) ◽  
pp. 1163-1165 ◽  
Author(s):  
M. B. Perry ◽  
Ann C. Webb
Keyword(s):  
Acetic Anhydride ◽  
Sodium Acetate ◽  
Partition Chromatography ◽  
Borohydride Reduction

2-Amino-2-deoxyhexoses can be analyzed by gas–liquid partition chromatography of their 2-acet-amido-1,3,4,5,6-penta-O-acetyl-2-deoxyglycitol derivatives prepared by borohydride reduction of the aminoglycoses followed by acetylation of the resulting aminoglycitols with acetic anhydride in the presence of sodium acetate.

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