Carbocyclic Phosphonate-Based Nucleotide Analogs Related to PMEA. I. Racemic trans-Configured Derivatives

1996 ◽  
Vol 61 (2) ◽  
pp. 313-332 ◽  
Author(s):  
Radek Liboska ◽  
Milena Masojídková ◽  
Ivan Rosenberg
Keyword(s):  
Ring Opening ◽  
Oxirane Ring ◽  
Nucleotide Analogs ◽  
Heterocyclic Bases ◽  
Derivatives Of

Racemic trans-N-(2-phosphonomethoxycycloalkyl) derivatives of heterocyclic bases, a novel type of nucleotide analogs related to 9-(2-phosphonomethoxyethyl)adenine (PMEA), are reported. The synthesis of fully protected adenine- (5), hypoxanthine- (7), guanine- (11), thymine- (13), uracil- (16) and cytosine-containing (18) carbocyclic nucleotide analogs is based on the reaction of trans-2-hydroxycycloalkyl derivatives of N-protected nucleobases (2, 10, 12, 14, 17) with diisopropyl tosyloxymethanephosphonate. Deprotection of these compounds afforded the title nucleotide analogs. The starting nucleoside derivatives have been prepared via nucleophilic oxirane ring opening of cycloalkene oxides with various protected or free nucleobases.

Carbocyclic Phosphonate-Based Nucleotide Analogs Related to PMEA II. Racemic cis-Configured Derivatives

1996 ◽  
Vol 61 (5) ◽  
pp. 778-790 ◽  
Author(s):  
Radek Liboska ◽  
Milena Masojídková ◽  
Ivan Rosenberg
Keyword(s):  
Ring Opening ◽  
Nucleoside Analogs ◽  
Mitsunobu Reaction ◽  
Nucleotide Analogs ◽  
Heterocyclic Bases ◽  
Derivatives Of

Racemic N-(cis-2-phosphonomethoxycycloalkyl) derivatives of heterocyclic bases, a novel type of nucleotide analogs related to 9-(2-phosphonomethoxyethyl)adenine (PMEA), are reported. The synthesis of adenine- (6a, 6b), uracil- (6c) and cytosine- (6d) containing carbocyclic phosphonates is based on the reaction of cis-2-hydroxycycloalkyl derivatives of protected nucleobases with diisopropyl tosyloxymethanephosphonate. The starting purine-containing nucleoside analogs 5a-5f were prepared by the Mitsunobu reaction of protected nucleobases with trans-2-benzyloxycycloalkanols, whereas pyrimidine-containing nucleoside analogs 5g-5k were obtained by configurational inversion at C-2' of the corresponding 1-(trans-2-hydroxycycloalkyl)pyrimidines via ring opening of their 2,2'-anhydro derivatives.

scholarly journals Novel Functional Derivatives of Methyl-cis-9,10-Epoxy-Octadecanoate

2010 ◽  
Vol 4 (3) ◽  
pp. 167-170
Author(s):  
Stanislav Skachko ◽  
◽  
Orest Hevus ◽  
Larysa Dolynska ◽  
◽  
...  
Keyword(s):  
Methyl Ester ◽  
Ring Opening ◽  
Acid Methyl Ester ◽  
Ester Group ◽  
Oxirane Ring ◽  
Acid Methyl ◽  
Functional Derivatives ◽  
Surface Active ◽  
Derivatives Of ◽  
Epoxystearic Acid

The synthesis of functional derivatives of epoxystearic acid methyl ester by oxirane ring opening and transesterification of ester group has been described. Some novel surface-active and peroxide-containing compounds have been obtained. Major features of the process have been investigated and main characteristics have been determined.

Some 1-substitution derivatives of 4-aryl-2,3-dihalogeno-1-naphthols

1984 ◽  
Vol 49 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Jiří Křepelka ◽  
Drahuše Vlčková ◽  
Milan Mělka
Keyword(s):  
Thionyl Chloride ◽  
Oxirane Ring ◽  
Secondary Amines ◽  
Two Phase ◽  
Lytic Effect ◽  
Primary And Secondary Amines ◽  
Phase Medium ◽  
Chloro Derivatives ◽  
Derivatives Of

Alkylation of derivatives of 4-aryl-1-naphthols (I-V) by 2,3-epoxypropyl chloride in methanolic sodium hydroxide gave epoxy derivatives VI, VIII, IX, XI and XII, apart from products of cleavage of the oxirane ring, VII and X. Analogous alkylation of compounds I, IV and V by 2-(N,N-diethylamino)ethyl chloride hydrochloride in a two-phase medium afforded basic ethers XIII to XV. The cleavage of the oxirane ring in compound VI by the action of primary and secondary amines, piperidine and substituted piperazines led to compounds XVI-XXIV. Reaction of thionyl chloride with compounds XXI, XXII and XXIV gave chloro derivatives XXV-XXVII.Exposure of compound XXII to 4-methylbenzenesulfonyl chloride produced compound XXVIII, retaining the secondary alcoholic group. In an antineoplastic screening in vivo none of the compounds prepared had an appreciable activity. Compound XVII, being an analogue of propranolol, was used in the test of isoproterenolic tachycardia, and showed a beta-lytic effect comparable with that of propranol.

Derivatives of isatin in aqueous solution. I. Kinetics of ring opening of Isatin-5-sulfonate

1981 ◽  
Vol 34 (2) ◽  
pp. 365 ◽  
Author(s):  
H Stunzi
Keyword(s):  
Ring Opening ◽  
Rate Of Change ◽  
Spectroscopic Methods ◽  
Ph Values ◽  
Buffer Region ◽  
Pka Value ◽  
Back Titration ◽  
Kinetics Of ◽  
Derivatives Of ◽  
Sulfonate Anion

The reactions of isatin-5-sulfonate anion (si-) which cause a hysteresis in pH titrations were studied by pH-metric and n.m.r, spectroscopic methods. Rapid alkalimetric titrations [I 0.15 M (KNO3),37�] gave the pKa value corresponding to the addition of OH- to si- [pKa(ring) 9.55]. The slow ring opening to the sulfonatoisatate dianion (sia2-) led to a drift of the pH values towards an equilibrium buffer region. Its pKa, value [pKa(eq) 3.44] corresponds to the reaction si-+H2O ↔ sia 2-+H+ Rapid back-titration gave the pKa value of the ring-opened species Hsia- [pKa(open) c. 1.3]. The rate law for the ring opening d[sia]/dt=k2 [siOH](OH)+k1*[si] was obtained from the rate of change of pH. N-Methylisatin-5-sulfonate behaves analogously.

An analysis of the factors contributing to the regioselectivity observed in the opening of oxiranes

1980 ◽  
Vol 58 (3) ◽  
pp. 302-306 ◽  
Author(s):  
Margaret M. Kayser ◽  
Peter Morand
Keyword(s):  
Oxygen Atom ◽  
Ring Opening ◽  
Oxirane Ring ◽  
Epoxide Ring ◽  
Acid Base ◽  
Epoxide Ring Opening ◽  
Soft Acid ◽  
Hsab Theory

The regioselectivity of epoxide ring opening can be analyzed in terms of hard–soft acid–base (HSAB) theory. The coordination of the hard acid with the oxygen atom of the oxirane ring produces a "pulling effect" which determines the direction of the ring opening. In the absence of a strong "pulling effect" the "pushing effect" of the approaching base is examined and the consequences of relative softness or hardness of the nucleophile on the regioselectivity of the ring opening are discussed.

Synthesis and Biological Effects of N-(2-Phosphonomethoxyethyl) Derivatives of Deazapurine Bases

1993 ◽  
Vol 58 (6) ◽  
pp. 1419-1429 ◽  
Author(s):  
Hana Dvořáková ◽  
Antonín Holý
Keyword(s):  
Biological Effects ◽  
Sodium Hydride ◽  
Cesium Carbonate ◽  
Cytostatic Effect ◽  
Phosphonic Acids ◽  
Dna Viruses ◽  
Purine Bases ◽  
Heterocyclic Bases ◽  
L 1210 Leukemia ◽  
Derivatives Of

Analogs of antiviral 9-(2-phosphonomethoxyethyl)adenine (PMEA,II), containing modified purine bases 1-deazaadenine (VII, 3-deazapurine (XI), 7-deaza-7-cyanoadenine (XIIIb) and 3-deazaguanine (XXIb) were prepared by alkylation of the heterocyclic bases with bis(2-propyl) 2-chloroethoxymethylphosphonate (V) in dimethylformamide in the presence of sodium hydride or cesium carbonate. The obtained protected derivatives were deblocked with bromotrimethylsilane to give the phosphonic acids. 3-DeazaPMEG (XXIb) is active against DNA viruses and exhibits a marked cytostatic effect against L-1210 leukemia.

Are amines basic or nucleophilic catalysts for oxirane ring opening by proton-donating nucleophiles?

2016 ◽  
Vol 57 (1) ◽  
pp. 47-51 ◽  
Author(s):  
S. G. Bakhtin ◽  
E. N. Shved ◽  
Yu. N. Bespal’ko
Keyword(s):  
Ring Opening ◽  
Oxirane Ring ◽  
Nucleophilic Catalysts
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