Oxidative cyclization of 1-octadecanol and hydroxy fatty esters with lead tetraacetate

1984 ◽  
Vol 61 (6) ◽  
pp. 1024-1027 ◽  
Author(s):  
M. Hashmi ◽  
M. Khan ◽  
M. S. Ahmad ◽  
F. Ahmad ◽  
S. M. Osman
Keyword(s):  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Fatty Esters

ChemInform Abstract: OXIDATIVE CYCLIZATION OF 1-OCTADECANOL AND HYDROXY FATTY ESTERS WITH LEAD TETRAACETATE

1984 ◽  
Vol 15 (46) ◽  
Author(s):  
M. HASHMI ◽  
M. KHAN ◽  
M. S. JUN. AHMAD ◽  
F. AHMAD ◽  
S. M. OSMAN
Keyword(s):  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Fatty Esters

Oxidative cyclization of carbonyl derivatives. 5-Imino-Δ1-1,2,4-triazolines from alkylideneimino guanidines

1978 ◽  
Vol 56 (16) ◽  
pp. 2194-2196 ◽  
Author(s):  
Lubomira M. Cabelkova-Taguchi ◽  
John Warkentin
Keyword(s):  
Sodium Carbonate ◽  
Oxidation Product ◽  
Methylene Chloride ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Carbonyl Derivatives ◽  
A Minor ◽  
Major Oxidation

Treatment of 2-propylideneimino guanidinium acetate with lead tetraacetate, in methylene chloride containing solid sodium carbonate, afforded the previously unknown 3,3-dimethyl-5-imino-Δ1-1,2,4-triazoline. Similarly, N,N′-diphenyl-N″-(2-propylideneimino)guanidinium acetate afforded Z-4-phenyl-5-phenylimino-Δ1-1,2,4-triazoline as the major oxidation product and the corresponding E isomer as a minor product. Stereochemistry was established spectrophotometrically and also by isomerizing the minor (E) isomer to the major (Z) isomer.

ChemInform Abstract: OXIDATIVE CYCLIZATION OF UNSATURATED FATTY ACIDS WITH LEAD TETRAACETATE

1983 ◽  
Vol 14 (51) ◽  
Author(s):  
M. HASHMI ◽  
M. KHAN ◽  
M. S. JUN. AHMAD ◽  
F. AHMAD ◽  
S. M. OSMAN ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate

Synthesis of Some 1H-1,2,4-Triazole, 4H-1,2,4-Triazole, Thiazolo[2,3-c]-1,2,4-triazole and 5H-1,2,4-Triazolo-[3,4-b][1,3]thiazine Derivatives by Metal Compound-Mediated Oxidative Cyclization of Derivatives of 2-(Phenylmethylidene)hydrazinecarboximidothioic Acid

1997 ◽  
Vol 50 (9) ◽  
pp. 911 ◽  
Author(s):  
Abdelselam S. Ali ◽  
John S. Wilkie ◽  
Kevin N. Winzenberg
Keyword(s):  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Metal Compound ◽  
Cyclization Reactions ◽  
Triazole Derivatives ◽  
Derivatives Of

Reaction of the methyl 2-(phenylmethylidene)hydrazinecarboximidothioate derivatives (3a–d) and (6a,b) with iron(III) chloride afforded the 5-methylsulfanyl-3-phenyl-4H-1,2,4-triazole derivatives (4a–d) and the 5-methylsulfanyl-3-phenyl-1H-1,2,4-triazole derivatives (7a,b). This reaction was extended to the synthesis of the 3-phenyl-5,6-dihydrothiazolo[2,3-c]-1,2,4-triazole derivatives (10a,b) and the 3-phenyl-6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3]thiazine derivatives (10c,d). Reaction of 5-(3-chlorophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (12a) with 1,2-dibromoethane gave (10a) together with the isomeric 2-(3-chlorophenyl)-5,6-dihydrothiazolo[3,2-b][1,2,4]triazole (13a); similarly, reaction of (12a) with 1,3-dibromopropane afforded (10c) along with 2-(3-chlorophenyl)-6,7-dihydro-5H-[1,2,4]triazolo[5,1-b][1,3]thiazine (13b). The use of nickel peroxide and lead tetraacetate in place of iron(III) chloride was investigated for some of these oxidative cyclization reactions.

Oxidative cyclization of unsaturated fatty acids with lead tetraacetate

1983 ◽  
Vol 60 (8) ◽  
pp. 1538-1543 ◽  
Author(s):  
M. Hashmi ◽  
M. Khan ◽  
M. S. Ahmad ◽  
F. Ahmad ◽  
S. M. Osman
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate

Diaryloxycarbenes from oxadiazolines

2001 ◽  
Vol 79 (3) ◽  
pp. 319-327
Author(s):  
Xiaosong Lu ◽  
Darren L Reid ◽  
John Warkentin
Keyword(s):  
Acidic Solution ◽  
Benzene Solution ◽  
Subsequent Treatment ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Dimethyl Acetylenedicarboxylate ◽  
Mild Conditions ◽  
Product Mixture ◽  
Carbonyl Ylide ◽  
Ketene Acetal

Symmetric and unsymmetric 2,2-diaryloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazolines were synthesized by oxidative cyclization of aryloxycarbonyl hydrazones of acetone with lead tetraacetate and subsequent treatment of the product mixture with a phenol in acidic solution. Thermolysis of the oxadiazolines in benzene solution at 110°C afforded carbonyl ylide intermediates that cyclize, in part, to the corresponding 2,2-diaryloxyoxirane intermediates. The oxiranes, which were not observed, are required to account for the 1,1-diaryloxy-2-methylpropenes (ketene acetals) that were isolated. Most of the carbonyl ylides fragment to acetone and diaryloxycarbenes. The latter form dimers (tetraaryloxyethenes) or they can be trapped with phenols to form orthoformates. Diphenoxycarbene was also trapped with dimethyl acetylenedicarboxylate (DMAD). The method appears to be the first for generating the parent diphenoxycarbene under relatively mild conditions in solution, and the only one to date for generating unsymmetrically substituted diaryloxycarbenes. Minor competing fragmentations of the oxadiazolines to 2-diazopropane and the appropriate diaryl carbonates, were also observed.Key words: diarylcarbonate, diaryloxycarbene, diaryloxy oxadiazoline, ketene acetal, orthoformate.

THE OXIDATION OF 3-(N-BENZYLACETAMIDO)-1,2-PROPANEDIOL TO N-BENZYLACETAMIDOACETALDEHYDE AND RING CLOSURE OF THE LATTER TO ISOQUINOLINEL

1955 ◽  
Vol 33 (2) ◽  
pp. 365-374 ◽  
Author(s):  
Arlen W. Frank ◽  
C. B. Purves
Keyword(s):  
Acetyl Derivative ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Ring Closure ◽  
Diethyl Acetal ◽  
Sodium Metaperiodate

Fischer's synthesis of isoquinoline by the oxidative cyclization of benzylaminoacetaldehyde diethyl acetal with 20% oleum was found to give a yield of 8.5%, but his isolation of the intermediate aldehyde could not be repeated. The N-acetyl derivative, N-benzylacetamidoacetaldehyde, however, was synthesized as a somewhat unstable oil, b.p. 129–131° (0.12 mm.), and was cyclized in 7.5% yield to isoquinoline. This synthesis involved the hydrogenation of 3-benzylideneamino-1,2-propanediol to 3-benzylamino-1,2-propanediol, b.p. 152-155° (0.5 mm.); hydrochloride, m.p. 92–94.5°. The N-acetyl derivative, 3-(N-benzylacetamido)-1,2-propanediol, b.p. 188° (0.12 mm.), was then oxidized with sodium metaperiodate; the behavior of other intermediates in the synthesis toward periodate, and also lead tetraacetate, was studied. The following additional compounds were thought to be new: 3-veratrylideneamino-1,2-propanediol, m.p. 123–125°; 3-veratrylamino-1,2-propanediol, b.p. 207–214° (0.4 mm.); the hydrochloride, m.p. 151–152°; 3-(N-benzylacetamido)-1,2-diacetoxypropane, b.p. 196–199° (0.7 mm.), and N-benzylacetamidoacetaldehyde 2,4-dinitrophenylhydrazone, m.p. 315–316°.

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