Dérivés d'énose‐ et d'ynosephosphonates et composés voisins. Communication préliminaire

Abstract

Derivatives of enose-and ynosephosphonates and related compoundsPreliminary communication SummaryThe gem-dibromo terminal enoses 1 and 7 are convenient sources of glycosylacetylenes which upon reaction with phosphorus electrophiles gave the phosphorusbearing acetylenic sugars 4, 5 and 8. Compounds 5 and 8 underwent cycloaddition reactions leading to isoxazolyl-C-glycosides 6 and 9 respectively. The nitroolefinic sugar derivative 11 gave upon bromination-dehydrobromination the first example of a new kind of potentially useful synthetic intermediates, the gem-bromonitroenose 12. The enosephosphonate 13 was also prepared from 111. The diglycosylhydroxylamine 18 represents another type of phosphorus-bearing acetylenic sugar derivative. Some 'H-and 13C-NMR. data relative to the new tylpes of phosphoruscontaining sugar derivatives synthesized are given.L'activitt anticancereuse de certains accepteurs de Michaei' derivts de sucres [2], de m&me que l'inter&t biologique potentiel de sucres phosphorts qui, de plus, constituent des modeles particulithement riches pour l'ttude par RMN. de couplages a longue distance 31P, l3C et 31P, 'H, nous a amene a prkparer quelques dialkoxyphosphinylenoses et dialkoxyphosphinylynoses ainsi lque des composes apparentes. Nous montrerons ultCrieurement que certains des nouveaux types de dtrives de sucres dkcrits ci-dessous3) sont des intermtdiaires de synthese tres riches.La phosphine 4 (sirop, Sucres phosphores 111; 11: 111. Une communication plus detaillee paraitra ulteneurement. Les analyses dementaires et les donntes spectroscopiques (UV., IR., RMN., SM.) de tous les nouveaux composCs decrits sont en accord avec la structure proposee.[

Structure-activity relationship between the 3D distribution of the electrophilicity of sugar derivatives and their cytotoxic and antiviral properties

“…This difference in regioselectivity can be explained by the fact that the nitro group is a better leaving group than the cyano group, which allows an addition-elimination reaction. Experimentally, sugars of type 2 were indeed shown to lose their nitro group easily [14]. The same calculations performed on a limited number of cyano-(3) and nitrochromenes (4) show the same general tendencies as those noted for 1 and 2 respectively, with compound 3 acting as a pure Michael acceptor (Fig.…”

Dialkyl 1-Alkynylphosphonates: a Range of Promising Reagents

“…These compounds were readily obtained from dialkyl or diphenyl chlorophosphates and the appropriate terminal alkynylmagnesium bromide, which was prepared in turn from the alkyne 21 and ethylmagnesium bromide in Et 2 O or THF (Scheme 9). [56] The most widely employed phosphorus reagent is diethyl chlorophosphate 19 (R = Et) which is reacted with the alkynylmagnesium bromide through direct [33,34,57] or inverse [56] addition at 0°C in Et 2 O or at -30°C in THF. This procedure has been successfully employed for the preparation of a variety of dialkyl 1-alkynylphosphonates 3 in fair to good yields (51 to 76%), with the best results generally obtained using addition of the alkyne salt to the chlorophosphate.…”

“…Other 1,3-dipoles such as C-aryl-N-phenylnitrones, [98] para-substituted phenylazides, [99,100] azidoalkylcarboxylates [97,101] and azidoalkylphosphonates, [102] C-substituted-N-arylnitrilimines, [103] para-substituted benzonitrile oxide [57,97] and N-phenylsydnone [104] react with diethyl 1alkynylphosphonates 13. They gave respectively, 5-isoxazolinephosphonates 48 in 42-72% yield, [98] 1-aryl-4-triazolylphosphonates 49, [95][96][97] 1-carboxyalkyl- [97,101] and 1-phosphonoalkyl-4triazolylphosphonates, [102] 4-or 5-pyrazolylphosphonates 50 and 51, [103] 4-isoxazolinephosphonate in 80-92% yields [57,97] and 3-pyrazolylphosphonates in 53% yield [104] (Figure 2). The reactivity of phosphorylated propynes and the chemo-and regioselectivity of these reactions is controlled both by donor-acceptor interactions between the reactants and the steric requirements of their substituents.…”

Acetylenosaccharides

“…Thus, 1,3-dipolar cycloadditions to azides, diazoalkanes, azomethine imines, and nitrile oxides have provided triazoles, pyrazoles, pyrazolines, and isoxazoles, respectively [93, 96,[203][204][205][206][207][208][209][210] (for a recent monograph on 1,3-dipolar cycloadditions, see [211]). Cyclocondensations of propiolaldehydes and 2-ynones with hydrazines or hydroxylamine have given pyrazoles and isoxazoles [212][213][214][215].…”