TETRAHYDROFURANS: I. 2,2-DIMETHYL-4-SUBSTITUTED-4-HYDROXYMETHYLTETRAHYDROFURANS AND RELATED COMPOUNDS

1961 ◽  
Vol 39 (4) ◽  
pp. 923-932 ◽  
Author(s):  
B. K. Wasson ◽  
C. H. Gleason ◽  
I. Levi ◽  
J. M. Parker ◽  
L. M. Thompson ◽  
...  
Keyword(s):  
Acetic Anhydride ◽  
Pharmacological Activity ◽  
Lithium Aluminum Hydride ◽  
Catalytic Reduction ◽  
Aluminum Hydride ◽  
Mineral Acid ◽  
Lithium Aluminum ◽  
Pyridine Hydrochloride ◽  
Cyclic Compounds ◽  
Related Compounds

Substituted methallylmalonic esters (I) were reduced with lithium aluminum hydride to the corresponding 2-methallyl-1,3-propanediols (II). These diols II underwent cyclization on treatment with a mineral acid to the isomeric 2,2-dimethyl-4-substituted-4-hydroxymethyltetrahydrofurans (IV). II and IV were converted to the respective carbamates III and V, which exhibited pharmacological activity. The assigned structures of the cyclic compounds IV were proved by infrared analyses and the following transformations. Ring scission of 2,2-dimethyl-4-allyl-4-hydroxymethyltetrahydrofuran (IVe) with acetic anhydride – pyridine hydrochloride yielded 2-allyl-2-methallyl-1,3-propanediol diacetate (Xe). Catalytic reduction of IVe gave 2,2-dimethyl-4-n-propyl-4-hydroxymethyltetrahydrofuran (IVd). Reductive cleavage of the tosylate VIIIb of 2,2,4-trimethyl-4-hydroxymethyltetrahydrofuran (IVb) with lithium aluminum hydride yielded the known 2,2,4,4-tetramethyltetrahydrofuran (IXb).

Derivatives of 2-pyrazolin-5-one. V. Preparation and properties of 1′,2′-dihydrospiro[[2]pyrazoline-4,3′ (4′H)-quinoline]-5-one.derivatives and related compounds

1977 ◽  
Vol 55 (15) ◽  
pp. 2856-2866 ◽  
Author(s):  
Ronald T. Coutts ◽  
Abdel-Monaem El-Hawari
Keyword(s):  
Acetic Acid ◽  
Sodium Borohydride ◽  
Lithium Aluminum Hydride ◽  
Catalytic Reduction ◽  
Aluminum Hydride ◽  
Spiro Compounds ◽  
Lithium Aluminum ◽  
Aldehydes And Ketones ◽  
Derivatives Of ◽  
Related Compounds

1′,2′-Dihydro-3-methyl-1-phenylspiro[[2]pyrazoline-4,3′(4′H)-quinoline]-5-one (8q), the structurally related 1,3-diphenylspiro[pyrazolone-quinoline] 8r and numerous 2′-substituted derivatives of 8q and 8r are readily accessible from catalytic reduction of 3-methyl-1-phenyl- or 1,3-diphenyl-4-(2-nitrobenzyl)-2-pyrazolin-5-one (1a, 1b, respectively) in alcohols (with the incorporation of the alkylidene moiety) or by interaction of the corresponding 2-aminobenzyl precursors (3a, 3b) with appropriate aldehydes and ketones. All spiro compounds were characterized by mass, ir, and 1Hmr spectra. The products obtained by reducing the spiro compounds with sodium borohydride and with lithium aluminum hydride are described. Reduction of 1a and 1b with zinc and acetic acid gave 3-methyl-1-phenyl- and 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline (2a, 2b, respectively).

REACTION MECHANISM STUDIES: 2. REDUCTIVE ELIMINATION OF 1,2-DIHALIDES WITH LITHIUM ALUMINUM HYDRIDE

1964 ◽  
Vol 42 (6) ◽  
pp. 1294-1314 ◽  
Author(s):  
J. F. King ◽  
R. G. Pews
Keyword(s):  
Reaction Mechanism ◽  
Lithium Aluminum Hydride ◽  
General Scheme ◽  
Aluminum Hydride ◽  
Reductive Elimination ◽  
Lithium Aluminum ◽  
Elimination Reaction ◽  
Complex Hydrides ◽  
Steric Factors ◽  
Related Compounds

1,2-Dibromides and bromohydrin p-toluenesulphonates of favorable geometry are readily reduced by lithium aluminum hydride in good yield to the corresponding olefin. Small quantities of water are found to have a temporaryacceleratingeffect on the reduction. The normal course of the reaction is a trans elimination, but when steric factors inhibit this, then substitution or cis elimination reactions may occur. It is shown that the cis elimination in the case of cis-1,2-dibromocyclohexane cannot involve reduction to the monobromide followed by dehydrobromination to the olefin. The reaction of some other 1,2-dihalides and related compounds with lithium aluminum hydride, and the reaction of a 1,2-dibromide with a number of other complex hydrides are reported.A general scheme for the mechanism of the olefin-forming elimination reaction is proposed. The limits that this study places on the possible positions of the reductive elimination of 1,2-dibromides with lithium aluminum hydride within this general scheme are discussed.

THE STRUCTURE OF MITRAPHYLLINE

1958 ◽  
Vol 36 (7) ◽  
pp. 1031-1038 ◽  
Author(s):  
J. C. Seaton ◽  
R. Tondeur ◽  
Léo Marion
Keyword(s):  
Double Bond ◽  
Experimental Evidence ◽  
Aromatic Amine ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Mineral Acid ◽  
Lithium Aluminum ◽  
Spectroscopic Evidence ◽  
Mild Conditions ◽  
Total Structure

Mitraphylline (C21H24O4N2) contains a carbomethoxyl group, and on hydrolysis gives rise to mitraphyllic acid. Spectroscopic evidence shows that the alkaloid contains two chromophores, one characteristic of an oxindole and one corresponding to the grouping CH3OOC—Ć==CH.OR. On treatment with dilute mineral acid the alkaloid gives rise to mitraphyllal (C19H24O3N2), which is a hemiacetal that no longer contains the isolated double bond and the carbomethoxyl group originally present in the alkaloid. Reduction of mitraphyllal by the Wolff–Kishner reaction gives mitraphyllane (C19H26O2N2). The dehydrogenation of mitraphyllal produced 3,4-diethylpyridine and 3-ethyloxindole. The action of lithium aluminum hydride on mitraphylline under mild conditions gave rise to mitraphyllol by reduction of the carbomethoxyl group, and under more vigorous conditions to dihydrodesoxy-mitraphyllol by reduction of the oxindole carbonyl as well. This last product has the properties of an aromatic amine. On the basis of the new experimental evidence, a total structure of mitraphylline is derived.

TETRAHYDROFURANS: II. SPIRO COMPOUNDS CONTAINING THE TETRAHYDROFURAN RING

1963 ◽  
Vol 41 (12) ◽  
pp. 3070-3073
Author(s):  
B. K. Wasson ◽  
J. A. Kernan ◽  
J. M. Parker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Mineral Acid ◽  
Spiro Compounds ◽  
Lithium Aluminum ◽  
Spectral Analyses ◽  
Nuclear Magnetic

2-Allyl-2-methallyl-1,3-propanediol (IV) and 2,2-dimethallyl-1,3-propanediol (V) were cyclized in the presence of mineral acid to give 3,3,8-trimethyl-2,7-dioxaspiro(4.4)nonane (VIII) and 3,3,8,8-tetramethyl-2,7-dioxaspiro(4.4)nonane (IX), respectively. Similarly, 2-methallyl-2-(3-methyl-2-butenyl)-1,3-propanediol (VI) afforded 3,3,8,8-tetramethyl-2,7-dioxaspiro(4.5)decane (X). The diol VI was derived from diethyl methallylmalonate by condensation with 3-methyl-2-butenyl bromide, followed by reduction of diethyl methallyl(3-methyl-2-butenyl)malonate (III) with lithium aluminum hydride. The assigned structures of the spiro compounds were supported by infrared and nuclear magnetic resonance spectral analyses.

Synthesis of Some Epiminocyclohexanes by Hydride Reduction of α,β-Unsaturated Cyclohexanone Oximes and the Pyrolytic cis-Elimination of N-Acetylepiminocyclohexanes

1973 ◽  
Vol 51 (3) ◽  
pp. 427-432 ◽  
Author(s):  
J. R. Dimmock ◽  
W. A. Turner ◽  
P. J. Smith ◽  
R. G. Sutherland
Keyword(s):  
Mass Spectrum ◽  
Reaction Mechanism ◽  
Acetic Anhydride ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Lithium Aluminum ◽  
Fragmentation Pathways ◽  
Hydride Reduction

Reduction of several 2-benzylidenecyclohexanone oximes with lithium aluminum hydride gave the corresponding 1-benzyl-1,2-epiminocyclohexanes. Reduction of 2-benzylidenecyclohexanone oxime with lithium aluminum deuteride gave an epiminocyclohexane (8) which had incorporated two deuterium atoms. A reaction mechanism for the reduction is postulated. The major fragmentation pathways in the mass spectrum of 8 are outlined. Acetylation of 1-benzyl-1,2-epiminocyclohexane with acetic anhydride (15 min reflux) gave 3-acetamido-2-benzyl-1-cyclohexene by a pyrolytic cis elimination.

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