A stereocontrolled synthetic entry to the primary prostaglandins from butadiene. Oxy anionic substituent effects on [1,5]-hydrogen sigmatropy

Paquette, Leo A.; Crouse, Gary D.; Sharma, Ashok K.

doi:10.1021/ja00531a060

Cited by 47 publications

(16 citation statements)

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“…In particular, it is well known that successful halocyclizations can accompany the formation of heterocyclic systems of this type, i.e. those containing five-membered rings mutually annelated [2,[18][19][20][21][22][23][24]. On the other hand, it turns out that not each six-membered 1-N-allyl-substituted Alk _______ *We have shown that the reaction of 1-allyl-3-(2-hydroxyethyl)-1H-quinazoline-2,4-dione with molecular bromine in glacial acetic acid also occurs with addition of the halogen to the allyl double bond, i.e.…”

Section: _______mentioning

confidence: 99%

4-hydroxy-2-quinolones 170*. synthesis and bromination of N-allylisatin

Украинец

Bereznyakova

Gorokhova

et al. 2009

Chem Heterocycl Comp

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Independently of the reaction conditions N-allylisatin forms only the 2,3-dibromo derivative upon treatment with molecular bromine in contrast to N-allyl-substituted quinolin-or pyrid-2-ones which readily undergo halocyclization to the corresponding 2-bromomethyl oxazoles.Decolorization of bromine is one of the widest known analytical reactions for alkenes but does not always prove to be due to the conventional addition of halogen to an unsaturated bond. With the existence of certain structural features such reactions can be accompanied by the formation of novel 5-, 6-and even 7-membered rings thanks to which they are often referred to as bromo-or halocyclizations [2][3][4][5][6][7].This type of chemical reaction occurs in the bromination of N-allyl-substituted 4-hydroxy-2-quinolones which is, in principle, a simple method for preparing 4R-2-bromomethyl-1,2-dihydrooxazolo[3,2-a]quinolines [8][9][10]. For evaluating the synthetic potential of this interesting reaction and to work out a fuller and more proven idea of the actual mechanism occurring in these chemical processes there is much value in the accumulation and subsequent analysis of experimental material including the maximum use of a broad range of model compounds.This report is a part of such an investigation, the aim of which was a study of the behavior of N-allylisatin 1 (with a structural similarity to 4-hydroxy-2-quinolones) under conditions of bromination using molecular bromine. According to a known outline [11], the alkylation of isatin 2 principally needs its conversion to a sodium salt and used sodium ethylate in absolute ethanol or, indeed, NaH in anhydrous DMF. Preference is usually given to the latter variant since, in this case, the initial separation of the salt is not essential. However, from our data, the use of this method is far from always justified. At least with allyl bromide this reaction is much more conveniently carried out using the system DMSO/K 2 CO 3 . The N-alkylation occurs very rapidly at room temperature and in virtually quantitative yield.

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Section: _______mentioning

confidence: 99%

4-hydroxy-2-quinolones 170*. synthesis and bromination of N-allylisatin

Украинец

Bereznyakova

Gorokhova

et al. 2009

Chem Heterocycl Comp

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“…Fur ther treat ment of the acetal 12 with var i ous aque ous acid so lu tions re sulted in com plex mix tures. 13 Af ter great ef fort, the syn thesis of 13 was achieved as fol lows: Hy dro ly sis of 2 with hydro chlo ride in aque ous THF so lu tion af forded al de hyde 14, which was sub se quently re acted with MCPBA to yield the Baeyer-Villiger ox i da tion prod uct 13. The struc ture of 13 was con firmed by com par i son of the 1 H NMR spec tra with an au then tic sam ple pro vided by Renaud.…”

Section: Re Sults and Discussionmentioning

confidence: 99%

“…Chem i cal shifts are re ported in ppm rel a tive to TMS (tetramethylsilane) in the sol vents spec i fied. The mul ti plic ities of 13 C sig nals were de ter mined by DEPT tech niques. Mass spec tra (MS) were mea sured on a VGQUATTRO 5022 mass spec trom e ter.…”

Section: Gen Eralmentioning

confidence: 99%

“…The res i due was chromatographed on sil ica gel (elu tion with 4:1 hex ane/ethyl ac e tate) to yield 13 (0.15 g, 52%) as an oil: IR (CHCl3) 2843, 1775, 1682 cm -1 ; 1 H NMR (300 MHz, CDCl3) 9.79 (s, 1H), 6.88 (d, J = 1.8 Hz, 1H), 5.25-5.15 (m, 1H), 3.80-3.65 (m, 1H), 3.05-2.95 (m, 2H), 2.87 (dd, J = 18. 9, 9.9 Hz, 1H), 2.69 (dd, J = 18.9, 2.1 Hz, 1H); 13…”

Section: (3as*6ar*)-2-oxo-33a66a-tetrahydro-2h-cyclopenta[b]oxolementioning

confidence: 99%

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Synthesis of Iridoid Monoterpenes and Prostaglandins, via Photochemical Rearrangement of Bicyclo[2.2.1]hept‐5‐en‐2‐One

Tai

Yang

Yeh

et al. 2001

J Chinese Chemical Soc

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“…A CHgR y-lactones. This iodolactonization reaction was used by Raquette et al in their synthesis of a prostaglandin precursor 55 from 54 which could be reduced to 56 with tri-n-butylstannane (35).…”

Section: Oh X ^17^8mentioning

confidence: 99%

A free radical synthesis of Y-lactones using tri-n-butylstannyl iodoesters

Landgrebe

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This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advemced technology has been used to pho tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques is provided to help clarify notations which may appear on this reproduction.

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A stereocontrolled synthetic entry to the primary prostaglandins from butadiene. Oxy anionic substituent effects on [1,5]-hydrogen sigmatropy

Abstract: lished mesoionic compounds12 and heteroaromatic be-Work is currently underway in this laboratory defining the scope and limitations of these unique compounds, as well as studying their physical and chemical properties.

Cited by 47 publications

References 8 publications

4-hydroxy-2-quinolones 170*. synthesis and bromination of N-allylisatin

4-hydroxy-2-quinolones 170*. synthesis and bromination of N-allylisatin

Synthesis of Iridoid Monoterpenes and Prostaglandins, via Photochemical Rearrangement of Bicyclo[2.2.1]hept‐5‐en‐2‐One

A free radical synthesis of Y-lactones using tri-n-butylstannyl iodoesters

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