A New Synthesis of Unsaturated Acids. II. α,β-Olefinic Acids<sup>1,2</sup>

Carpino, Louis A.

doi:10.1021/ja01536a022

Cited by 15 publications

(1 citation statement)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 Because of the unusually extensive dehydrogenation observed in the reaction product of hydrazine with maleic and fumaric acids and their esters2 (reported to form 5-oxc-2pyrazoline-3-carbohydrazide), this reaction was reinvestigated. Spectral evidence indicates that the product obtained in this reaction is 5-oxo-3-pyrazoline-3-carbohydrazide (4) 0 NH.NHC NT Z=°H H 4 rather than the isomeric 5-oxo-2-pyrazoline previously assigned.2 Proton NMR spectroscopy shows a vinylic hydrogen (singlet) superimposed on a broad low intensity peak, and proton-coupled 13C NMR spectroscopy shows a doublet centered at 88.93 ppm (J = 178 Hz), corresponding to carbon 4, a doublet with small coupling at 138.34 ppm (J = 0.26 Hz, carbon 3), and a singlet at 160.08 ppm (coincidental carbonyls). The existence of coincidental carbonyl chemical shifts was verified by integration.7 The ultraviolet spectrum (Xmax 217 nm) supports the presence of a carbon-carbon double bond rather than a carbon-nitrogen double bond8 in the molecule.…”

mentioning

confidence: 91%

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Patterson¹,

Braun²,

Haidar³

et al. 1978

J. Org. Chem.

View full text Add to dashboard Cite

mentioning

confidence: 91%

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Patterson¹,

Braun²,

Haidar³

et al. 1978

J. Org. Chem.

View full text Add to dashboard Cite

Preparation of Difunctional Compounds

1974

Compendium of Organic Synthetic Methods

View full text Add to dashboard Cite

Diphenylacetylene from the Base‐Catalyzed Fragmentation of 3,6‐Dihydro‐5,6‐Diphenyl‐3‐Tosyl‐1,3,4‐Oxadiazin‐2‐One

Allen

Anselme

1995

Bulletin des Soc Chimique

View full text Add to dashboard Cite

Treatment of 3,6-dihydm-5,6-diphenyl-3-tosyl-I , 3,4-oxadiazin-2 ter than 70% yield.In the context of our work on 3-pyrazolidinones (1) and the related 3-oxopyrazolidinium ylides (2),' we had been interested in tetrahydro-1,3,4-oxadiazin-2-ones (3) which differ from 3-pyrazolidinones only by the presence of an oxygen in the ring. To our knowledge, the investigations of Rosenblum and his group2 remain the only report in that area. In both cases, it is likely that the cyclic a-carbonylazo intermediates,*-3 resulting from the oxidation of l a (R = R' = Ph)*.3 and of 3a (R = R' = Ph)? undergo extrusion of nitrogen and of either carbon monoxide or carbon dioxide, respectively, to give trans-stilbene. On the other hand, it is interesting to note that of the unsaturated analogues 4 and 6, only 4 undergoes a similar oxidativefragrnentation, albeit in very poor yield (14% yield of 6 b) cyclopentadiene 9 m t~l a n ) ;~ indeed, Carpinos had reported the formation of aphenylcinnamic acids (mixture of isomers) from the reaction of 6 with base, evidently by base-induced ring opening of 7; com--one with sodium hydride in THF afirds diphenylacetylene in betpound 7 is apparently sufficiently stable to be intercepted as the Diels-Alder adduct with cyclopentadiene.6In the course of our attempts to devise a preparation of 3s (R = R' = Ph) which would provide both stereoisomers and would not involve the use of sealed tube reactions,2 we synthesized a number of derivatives of 5,6-diphenyl-3,6-dihydro-1,3,4-oxadiazin-2-one (lo), including 3,6-dihydro-5,6-diphenyl-3-tosyl-1,3,4-oxadiazin-2-one (11). It was anticipated that 11 should undergo base-catalyzed 1 ,Celirnination to intermediate 5 which should then fragment to nitrogen, carbon dioxide and diphenylacetylene. Thus, it was gratifying to find that the reaction of 11 with sodium hydride in tetrahydrofuran (THF) at reflux smoothly and cleanly gave tolan in better than 10 11 70% yield. In contrast to 4, which was prepared by treatment of 10 with two equivalents of triphenylmethide, compound 11 was readily obtained as a pale tan solid, mp. 156-158", in 70% yield by treatment of 5,6-diphenyl-3,6-dihydro-1,3,4-oxadiazin-2-one (10) with sodium hydride in THF, followed by the addition of tosyl chloride. Diphenylacetylene could also be prepared directly from 10 in 65% yield by treatment of the tosylation reaction mixture with a second equivalent of sodium hydride.The facile transformation of the 1,3,4-oxadiazin-2-one ring to a triple bond in synthetically acceptable yields suggests that these compounds may be useful as masked alkynes and thus may prove to be valuable, especially in macrocyclic chemistry, since the required a-ketols, precursors of the 1,3,4-oxadiazin-2-ones may be obtained by the acyloin and the benzoin condensations.7-577 -Acknowledgements.-The support of this work by the Department of Chemistry is hereby gratefully acknowledged. Aberdeen Allen also thankful for the award of a Teaching Fellowship.

show abstract

A New Synthesis of Unsaturated Acids. II. α,β-Olefinic Acids^1,2

Cited by 15 publications

References 2 publications

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Preparation of Difunctional Compounds

Diphenylacetylene from the Base‐Catalyzed Fragmentation of 3,6‐Dihydro‐5,6‐Diphenyl‐3‐Tosyl‐1,3,4‐Oxadiazin‐2‐One

Contact Info

Product

Resources

About

A New Synthesis of Unsaturated Acids. II. α,β-Olefinic Acids1,2

Cited by 15 publications

References 2 publications

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Synthesis and pyrolysis of hydrazine and phenylhydrazine adducts of tetraethyl ethylenetetracarboxylate

Preparation of Difunctional Compounds

Diphenylacetylene from the Base‐Catalyzed Fragmentation of 3,6‐Dihydro‐5,6‐Diphenyl‐3‐Tosyl‐1,3,4‐Oxadiazin‐2‐One

Contact Info

Product

Resources

About

A New Synthesis of Unsaturated Acids. II. α,β-Olefinic Acids^1,2