Synthesis of 3-(5-Alkyl-4-acetyl(ethoxycarbonyl))-2-propenoates from Derivatives of 3-Phenoxy-2-furylmethylene

1992 ◽  
Vol 57 (8) ◽  
pp. 1684-1692 ◽  
Author(s):  
Štefan Marchalín ◽  
Vladimír Mlynárik ◽  
Anna Staňová ◽  
Dušan Ilavský
Keyword(s):  
Acid Hydrolysis ◽  
Hydrogen Chloride ◽  
Pure Form ◽  
Geometric Isomers ◽  
Transition Mechanism ◽  
One Step ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Trisubstituted Furans

3-(2-Furyl)propenoates IV-VIII were obtained by treatment of 5-phenoxy-2-furylmethylene derivatives I-III with alcoholic hydrogen chloride in one step. The probable transition mechanism of synthons I-III into the 2,4,5-trisubstituted furans is presented. The geometric isomers E-IV, Z-V and Z-VI, isolated in pure form, were transformed into the corresponding acids E-IX, Z-IX and E-X by base-catalyzed hydrolysis. Acid hydrolysis of the 1,3-diketone I afforded (4Z,6Z)-6-acetyl-7-hydroxy-2,4,6-octatrien-4-olide (XI). Structure of the products was verified by spectral (IR, UV, NMR and mass) methods.

Partial hydrolysis of acyl 1,6-anhydro-β-D-glucopyranose

1984 ◽  
Vol 49 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Štefan Kučár ◽  
Juraj Zámocký ◽  
Juraj Zemek ◽  
Dušan Anderle ◽  
Mária Matulová
Keyword(s):  
Acid Hydrolysis ◽  
Hydrazine Hydrate ◽  
Hydrogen Chloride ◽  
Ester Group ◽  
The Other ◽  
Hydroxyl Group ◽  
Partial Hydrolysis ◽  
Substantial Influence ◽  
Hydrolysis Of ◽  
Derivatives Of

Partial hydrolysis of per-O-acetyl- and per-O-benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose with methanolic hydrogen chloride and hydrazine hydrate was investigated. The acyl group at C(3) is of substantial influence on the course of hydrolysis. The esterified hydroxyl group at C(3) was found to be most stable on acid hydrolysis with methanolic hydrogen chloride when compared with that at C(2), or C(4); on the other hand, this ester group is the most labile upon hydrolysis with hydrazine hydrate. Selectivity of the respective ester groups towards hydrolysis made it possible to prepare all variations of acetyl and benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

1'-Derivatives of sucrose and their acid hydrolysis

1980 ◽  
Vol 33 (11) ◽  
pp. 2487 ◽  
Author(s):  
RD Guthrie ◽  
ID Jenkins ◽  
JJ Watters
Keyword(s):  
Acid Hydrolysis ◽  
Hydrolysis Of ◽  
Derivatives Of

Syntheses of 1'-chloro-1'-deoxy- and 1'-deoxy-sucrose are described. Several routes were investigated, the most successful being through 6,1',6'-tri-O-(2,4,6-trimethylbenzenesulfonyl)sucrose. Attempts to prepare 1'-deoxy-1'-fluorosucrose were unsuccessful. The rates of the acid-catalysed hydrolysis of 1'-chloro-1'-deoxysucrose and of 1'- deoxysucrose have been measured. These values are compared with that for sucrose itself. The mechanism of the hydrolyses is discussed.

ChemInform Abstract: KINETICS OF THE ACID HYDROLYSIS OF VINYL DERIVATIVES OF BENZIMIDAZOLE-2-THIONE, BENZOXAZOL-2-ONE AND -2-THIONE

1983 ◽  
Vol 14 (17) ◽  
Author(s):  
L. I. SVYATKINA ◽  
N. D. ABRAMOVA ◽  
L. L. DMITRIEVA ◽  
B. V. TRZHTSINSKAYA ◽  
G. G. SKVORTSOVA
Keyword(s):  
Acid Hydrolysis ◽  
Vinyl Derivatives ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Acid hydrolysis of N-methyl derivatives of 4-phenyl-5-oxo-4,5-dehydroindeno[1,2-b]pyridine

1986 ◽  
Vol 22 (10) ◽  
pp. 1104-1107 ◽  
Author(s):  
V. K. Lusis ◽  
D. Kh. Mutsenietse ◽  
G. Ya. Dubur
Keyword(s):  
Acid Hydrolysis ◽  
Methyl Derivatives ◽  
Hydrolysis Of ◽  
Derivatives Of

Synthesis of Enantiomeric N-(2-Phosphonomethoxypropyl) Derivatives of Purine and Pyrimidine Bases. I. The Stepwise Approach

1995 ◽  
Vol 60 (7) ◽  
pp. 1196-1212 ◽  
Author(s):  
Antonín Holý ◽  
Milena Masojídková
Keyword(s):  
Acid Hydrolysis ◽  
High Activity ◽  
Aluminum Hydride ◽  
Heterocyclic Base ◽  
Stepwise Approach ◽  
Pyrimidine Bases ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Very High

The (R)- and (S)-N-(2-phosphonomethoxypropyl) derivatives of purine and pyrimidine bases (PMP derivatives) exhibit very high activity against retroviruses. This paper describes the synthesis of enantiomeric 9-(2-phosphonomethoxypropyl)adenines (I and XXVII), 9-(2-phosphonomethoxypropyl)-2,6-diaminopurines (II and XXXI), 9-(2-phosphonomethoxypropyl)guanines (III and XXIX) and 1-(R)-(2-phosphonomethoxypropyl)cytosine (XIX) by alkylation of N-protected N-(2-hydroxypropyl) derivatives of the corresponding bases with bis(2-propyl) p-toluenesulfonyloxymethylphosphonate (X), followed by stepwise N- and O-deprotection of the intermediates. The key intermediates, N-(2-hydroxypropyl) derivatives IX and XXV, were obtained by alkylation of the appropriate heterocyclic base with (R)- or (S)-2-(2-tetrahydropyranyloxy)propyl p-toluenesulfonate (VII or XXIII) and acid hydrolysis of the resulting N-[2-(2-tetrahydropyranyloxy)propyl] derivatives VIII and XXII. The chiral synthons were prepared by tosylation of (R)- or (S)-2-(2-tetrahydropyranyloxy)propanol (VI or XXI) available by reduction of enantiomeric alkyl 2-O-tetrahydropyranyllactates V and XXI with sodium bis(2-methoxyethoxy)aluminum hydride. This approach was used for the synthesis of cytosine, adenine and 2,6-diaminopurine derivatives, while compounds derived from guanine were prepared by hydrolysis of 2-amino-6-chloropurine intermediates. Cytosine derivative IXe was also synthesized by alkylation of 4-methoxy-2-pyrimidone followed by ammonolysis of the intermediate IXf.

Hypoglucaemic triterpenoid saponins from Boussingaultiabaselloides

1990 ◽  
Vol 68 (11) ◽  
pp. 2039-2044 ◽  
Author(s):  
Alfonso Espada ◽  
Jaime Rodriguez ◽  
M. Carmen Villaverde ◽  
Ricardo Riguera
Keyword(s):  
Acid Hydrolysis ◽  
Chemical Transformation ◽  
Acid Treatment ◽  
Methanolic Extract ◽  
Transformation Products ◽  
Triterpenoid Saponins ◽  
Plant Metabolite ◽  
Hydrolysis Of ◽  
Derivatives Of

New saponins with hypoglucaemic activity (1–4) and momordin Ic (5) have been isolated from the methanolic extract of the leaves of Boussingaultiabaselloides. They were shown by spectroscopy and chemical transformation to be derivatives of 12,20(29)-dien-30-noroleanic acid. Boussingoside A1 (1) exhibits very strong hypoglucaemic activity in rats. Acid hydrolysis of the saponin 1 yielded five transformation products (6–10), though one of them (larreagenin A (6), which has been reported in the literature as a genuine plant metabolite) is considered to be an artifact formed by the acid treatment. Keywords: Boussingaultiabaselloides, Basellaceae, boussingosides, triterpenoid saponins, hypoglucaemic activity.

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