Lithiation of bridgehead positions in 3,6-bridged piperazine-2,5-diones

1982 ◽  
Vol 35 (11) ◽  
pp. 2289 ◽  
Author(s):  
FW Eastwood ◽  
D Gunawardana ◽  
GT Wernert
Keyword(s):  
Carbonyl Group ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Sodium Methoxide ◽  
Inductive Effect ◽  
Amide Nitrogen

2,5-Dimethyl-2,5 diazabicyclo[2,2,2]octane-3,6-dione can be lithiated at the 1,4 (bridgehead) positions with 2 equiv. of t-butyllithium at -78� and deuterated with D2O (Do, 11.2; Dl, 56.1 ; D2, 30.1%). With butyllithium and methyl iodide the 1,2,5-trimethyl and 1,2,4,5-tetramethyl derivatives are obtained. Treatment of dimethyl 2,6-diaminoheptanedioate dihydrochloride with sodium methoxide in boiling butanol gives 6,8-diazabicyclo[3,2,2]nonane-7,9-dione in 62% yield. N-Methylation of this compound yields 6,8-dimethyl-6,8-diazabicyclo[3,2,2]nonane-7,9-dione which can similarly be lithiated at the 1,5 (bridgehead) positions and deuterated with D2O (Do, 5.6; Dl, 70.8; D2, 23.6%). Lithiation with butyllithium and reaction with methyl iodide, benzyl iodide or bromomethyl methyl ether gives mono-and di-alkylated products at the 1,5-positions. The ability to lithiate the bridgehead positions in these compounds is attributed primarily to a combination of the inductive effect of the carbonyl group and dipole stabilization by the amide nitrogen.

STUDIES OF REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES.: XXVIII. THE STRUCTURE OF ISOPROPYLIDENE GLYCEROL

1930 ◽  
Vol 2 (3) ◽  
pp. 214-217 ◽  
Author(s):  
Harold Hibbert ◽  
J. G. Morazain
Keyword(s):  
Methyl Iodide ◽  
Methyl Ether ◽  
Copper Sulphate ◽  
Silver Oxide ◽  
Condensation Product ◽  
Neutral Medium ◽  
Physico Chemical ◽  
Isopropylidene Glycerol

Isopropylidene glycerol, prepared in neutral medium by the action of anhydrous copper sulphate as condensing agent, was methylated with silver oxide and methyl iodide; the product yielded only glycerol α-methyl ether on hydrolysis, thus proving the absence of any six-membered ketal in the condensation product of glycerol and acetone.The properties of both glycerol α- and β-methyl ethers have been carefully redetermined.A table of the isomeric acetals and ketals summarising their physico-chemical constants is given, in view of their usefulness as "type compounds" in investigations relating to fats, carbohydrates and polysaccharides.

ChemInform Abstract: (Z)- AND (E)-3-ALKYLIDENE-1,3-DIHYDROINDOL-2-ONES. INFLUENCE OF CONFIGURATION ON THE TRANSMISSION OF THE INDUCTIVE EFFECT TO THE CARBONYL GROUP

1976 ◽  
Vol 7 (14) ◽  
pp. no-no
Author(s):  
GIANFRANCO TACCONI ◽  
LUCIA DACREMA MAGGI ◽  
PIERPAOLO RIGHETTI ◽  
GIOVANNI DESIMONI ◽  
ORNELLA AZZOLINA ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Inductive Effect

Ultraviolet photoelectron spectra of 2-norbornanone, 2,5-norbornanedione, their alkyl derivatives and thio-analogues. An investigation of transannular interactions by photoelectron spectroscopy

1980 ◽  
Vol 58 (16) ◽  
pp. 1659-1665 ◽  
Author(s):  
David C. Frost ◽  
Nicholas P. C. Westwood ◽  
Nick H. Werstiuk
Keyword(s):  
Carbonyl Group ◽  
Photoelectron Spectroscopy ◽  
Inductive Effect ◽  
Photoelectron Spectra ◽  
Methyl Substitution ◽  
Bond Interaction ◽  
Alkyl Derivatives ◽  
Semi Empirical ◽  
Small Separation

HeI photoelectron spectra are reported for a series of methyl-substituted monoketones and diketones based on 2-norbornanone. The effect of methyl substitution, and the inductive effect of a second carbonyl group has been studied. The diketones show a small separation between the two ketone moieties due to a through-bond interaction. Replacement with a thiocarbonyl group permits a comparison of the relative C=S and C=O interactions. The relative merits of the semi-empirical HAM/3 and CNDO/2 methods for such molecules are assessed.

Rates of N-methylation of azoles with methyl iodide and dimethyl sulphate

1973 ◽  
Vol 26 (9) ◽  
pp. 1949 ◽  
Author(s):  
LW Deady
Keyword(s):  
Methyl Iodide ◽  
Dimethyl Sulphate ◽  
Inductive Effect ◽  
Reaction Rates ◽  
Dimethyl Sulphoxide ◽  
The Other

The rates of quaternization of various azoles and their benzo derivatives with dimethyl sulphate, and with methyl iodide in dimethyl sulphoxide, are reported. Reaction rates are controlled mainly by the inductive effect of the other hetero atom and there is a good correlation between rate of quaternization and basicity of the azole.

CYCLIC COMPOUNDS CONTAINING A CARBONYL GROUP; A MECHANISM FOR THE FORMATION OF PYRYLLIUM SALTS FROM 1,5-DIKETONES

1933 ◽  
Vol 9 (6) ◽  
pp. 574-582 ◽  
Author(s):  
C. F. H. Allen ◽  
H. R. Sallans
Keyword(s):  
Carbonyl Group ◽  
Methyl Ether ◽  
Ring Closure ◽  
Closed Ring ◽  
Second Mode ◽  
Ring Structures ◽  
Group A ◽  
Plausible Mechanism ◽  
Cyclic Compounds

In the presence of alkali, cyclohexanone and its homologues add to chalcones to form either semicyclic diketones or dicyclic keto-alcohols; the latter contain a carbonyl bridge, and the former can be converted into closed ring structures and dehydrated to form substances having a carbonyl bridge. In these dicyclic ketones the bridge is not removed by heating, in contrast to the behavior of certain other compounds having a similar ring system.A second mode of ring closure gives rise to pyryllium salts; the isolation of a methyl ether has made it possible to devise a plausible mechanism for this hitherto obscure reaction. Four varieties of salts are described, the perchlorates being obtained by a different procedure than that previously employed.

scholarly journals Synthesis of New Bis(spiro-β-lactams) via Interaction of Methyl 1-Bromocycloalcanecarboxylates with Zinc and N,N′-Bis(arylmethylidene)benzidines

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
N. F. Kirillov ◽  
E. A. Nikiforova ◽  
D. V. Baibarodskikh ◽  
T. A. Zakharova ◽  
L. S. Govorushkin
Keyword(s):  
Nitrogen Atom ◽  
Carbonyl Group ◽  
Nucleophilic Addition ◽  
Ring Closure ◽  
Amide Nitrogen ◽  
Ester Carbonyl ◽  
Ester Carbonyl Group ◽  
Amide Nitrogen Atom

Interaction of the Reformatsky reagents, prepared from methyl 1-bromocyclopentane-1-carboxylate or methyl 1-bromocyclohexane-1-carboxylate, with N,N′-bis(arylmethylidene)benzidines has given rise to a set of intermediates as a result of nucleophilic addition to the C=N group of a substrate. Further intramolecular attack of the amide nitrogen atom onto the ester carbonyl group is responsible for the ring closure, which affords two series of spirocompounds: 2,2′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-2-azaspiro[3.4]octan-1-one) or 2,2′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-2-azaspiro[3.5]nonan-1-ones).

ipso Nitration. XXIII. Reactions of cyclohexadiene adducts from nitration of 4-ethyltoluene in acetic anhydride

1981 ◽  
Vol 59 (15) ◽  
pp. 2314-2327 ◽  
Author(s):  
Alfred Fischer ◽  
George N. Henderson
Keyword(s):  
Sulfuric Acid ◽  
Acetic Anhydride ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Potassium Hydroxide ◽  
Silver Oxide ◽  
Aluminum Hydride ◽  
Trifluoroacetic Anhydride ◽  
Aqueous Methanol

The diastereoisomers of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate (1) and 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate (2) are stereospecifically reduced to the corresponding nitrocyclohexadienols with aluminum hydride. Each dienol is stereospecifically methylated to the corresponding methyl ether with methyl iodide, silver oxide, and potassium hydroxide. Acid-catalysed solvolysis of the acetates 1 and 2 results in the substitution of the acetate moiety by other nucleophiles and these reactions are not stereospecific. The products of rearomatization of dienyl acetates, dienols, and dienyl methyl ethers depend on the acidity and ionizing power of the solvents and are readily explained in terms of reactions involving a nitrocyclohexadienyl cation or acetoxy- (hydroxy-, methoxy-)cyclohexadienyl cation as key intermediates. In the 4-acetoxy-4-alkylcyclohexadienyl cation 1,2-migration of the acetoxyl group is more rapid than alkyl migration, but 1,2-alkyl migration is faster than migration of the hydroxyl or methoxyl groups in the corresponding cations. 1-Ethyl-4-methoxy-4-methylcyclohexa-2,5-dien-1-ol and 4-ethyl-3-nitrotoluene are significant minor products in the solvolysis of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dien-1-ol in aqueous methanol. Nitration of p-ethyltoluene in the presence of sulfuric acid or in trifluoroacetic anhydride gives a mixture of 4-ethyl-2-nitro- and 4-ethyl-3-nitrotoluene in a 2:1 ratio.

(Z)- and (E)-3-Alkyldine-1,3-dihydroindol-2-ones : influence of configuration on the transmission of the inductive effect to the carbonyl group

1976 ◽  
pp. 150 ◽  
Author(s):  
Gianfranco Tacconi ◽  
Lucia Dacrema Maggi ◽  
Pierpaolo Righetti ◽  
Giovanni Desimoni ◽  
Ornella Azzolina ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Inductive Effect
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