Cyclit‐Reaktionen, V. Synthese von enantiomerenreinem Valienamin aus Quebrachit

Paulsen, Hans; Heiker, Fred R.

doi:10.1002/jlac.198119811208

Cited by 61 publications

(15 citation statements)

References 29 publications

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“…They are used as flavouring agents 1 catalysts, 2 antibiotics 2,3 or reagents in organic synthesis. 4,5 The coordinating ability of the simple dithiazinanes was already tested using BX 3 reagents (X = H or halogen), in all cases the nitrogen is the more basic site, [6][7][8][9][10][11][12][13] …”

Section: Introductionmentioning

confidence: 99%

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Gálvez-Ruíz¹,

Solano-Ruiz²,

Sánchez-Ruíz³

et al. 2007

Arkivoc

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Compounds 2-(1,3,5-dithiazinan-5-yl)ethanol (1), 2-methyl-2-(1,3,5-dithiazinan-5-yl)ethanol (2) and 2-phenyl-2-(1,3,5-dithiazinan-5-yl)ethanol (3) reacted with BF 3 ⋅OEt 2 and BCl 3 ⋅DMS, 1 and 2 with (Ph 2 B)O, and 2 and 3 with GaCl 3 giving the corresponding chelates, bearing N→BF 2 O, N→BCl 2 O N→BPh 2 O, and N→GaCl 2 O groups. The internal coordination N→M (M = B or Ga) afforded spiro-compounds, where nitrogen is the central atom. Compounds were mainly characterized by 11 B, 1 H and 13 C NMR. The N→B or N→Ga coordination bond was detected in the 1 H spectra because coordination stops the ring inversion of the dithiazinane ring differentiating equatorial and axial protons. The presence of a sterogenic center at the ethanol arm (ligands 2 and 3), differentiates C4H 2 and C6H 2 upon coordination. Minimum energy structures for boron compounds were calculated [ab initio 6-31G(d,p)]. VT NMR experiments for diphenyl borinic esters were performed in order to estimate the N→BPh 2 coordination energy. X-ray diffraction analyses of the hydrochloride of ligand 1 and of the gallium compound prepared from 2 were obtained.

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Section: Introductionmentioning

confidence: 99%

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Gálvez-Ruíz¹,

Solano-Ruiz²,

Sánchez-Ruíz³

et al. 2007

Arkivoc

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“…In the corresponding Gala1-4Gal3l-4Glc sequence of globoside, a strong binder of PapGj96, the acetamido group is replaced by the HO-2 of Glc. The minimum energy conformation of the saccharides was calculated using the HSEA (Lemieux et al, 1980;Thorgersen et al, 1982) and GESA (Paulsen et al, 1984) programs. The conformational features of the ceramide part were adopted from the crystal structures of galactosylceramide (Pascher and Sundell, 1977) and other membrane lipids (Pascher et al, 1987).…”

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confidence: 99%

Host-specificity of uropathogenic Escherichia coli depends on differences in binding specificity to Gal alpha 1-4Gal-containing isoreceptors.

et al. 1990

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Four G adhesins, cloned from uropathogenic Escherichia coli strains, were examined for binding to glycolipids and various eukaryotic cells. PapGAD110 and PapGIA2 showed virtually identical binding patterns to Gal alpha 1‐4Gal‐containing glycolipids, while PapGJ96 differed slightly and PrsGJ96 markedly with respect to the effect of neighbouring groups on the binding. Their hemagglutination patterns confirmed the existence of three receptor‐binding specificities. While the PapG adhesins bound to uroepithelial cells from man (T24) but not to those from the dog (MDCK II), the reverse was true of PrsG. These binding patterns were largely explained by the absence or presence of appropriate glycolipid isoreceptors, although the inability of the PapG adhesins to bind MDCK II cells was attributed to an inappropriate presentation of their receptor epitopes. The high prevalence of PrsG‐like specificities observed among wild‐type dog uropathogenic E. coli isolates, together with the determined isoreceptor composition of human and dog kidney target tissues, suggest variation in receptor specificity as a mechanism for shifting host specificity, and that this variation has evolved in response to the topography of the host cellular receptors. The receptor‐binding half proposed for the predicted amino acid sequences of the four G adhesins and the corresponding adhesin of one of the dog E. coli isolates varied considerably among the three receptor‐binding groups of adhesins, but only little within each group.

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“…FAB-MS (calc. for C,,H,0,'20Sn): 718 (4,[(Ph,Sn),O]+), 716 (5), 707 (2, [ M -Ph]'), 351 (54,[SnPh,l+),181 (19), 91 (100).Anal.calc.forC4,H,0,Sn(783.55) 4,6-Di-0-henzyl-23-dideoxy-3-C-(triphenylstannyl~-a-~-nbo-hexopyranose (6) .8,4.6, 9.3, H-C(5)); 4.06 (d, J = 1 1.0, lH, PhCH,); 3.90 (dd, J = 5.9,9.5, H-C(4)); 3.69 (dd, J = 4.8, 10.7,HA-C(6)); 3.55 ( d d , J = 1.9, 10.6,HB-C(6)); 2.59 ('dt',J=2.6,5.5,H-C(3) (1)); 76.87 (d, J(Sn,C) = 29.4, C(4)); 72.90 (t); 72.57 (t); 70.67 (d,J(Sn,C) < 5, C(5)); 69.81 (t, C(6)); 32.24 (a, C(2)); 28.08 (d, J(Sn,C) = 449, (33)). '19Sn-NMR (C,,D,) 3 .68(dd,J=4.2, 10.9,HA-C(6));3.60(dd,J=2.2, 10.7,H,-C(6));3.54(ddd,J=2.1,4.5,8.8,H-C(5));2.75(d, General Procedure for the Synthesis of PC-Glucosides with 4.…”

Section: Experimental Partmentioning

confidence: 99%

Preparation and Transmetallation of a Triphenylstannyl β‐D‐Glucopyranoside: A highly stereoselective route to β‐D‐C‐glycosides via glycosyl dianions

Frey

Hoffmann

Wittmann

et al. 1994

Helvetica Chimica Acta

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The triphenylstannyl p-u-glucopyranoside 4 was synthesized in one step from the 1.2-anhydro-a-uglucopyranose 3 with (hiphenylstannyl)lithium (Scheme 1). Transmetallation of 4 with excess BuLi, followed by quenching the dianion 7 with CD,OD gave (1s)yield (Scheme 2). Trapping of 7 with benzaldehyde, isobutyraldehyde, or acroleine gave the expected p-Dconfigurated products 11,12, and 13 in good yields. Preparation of C-acyl glycosides from acid chlorides, such as acetyl or benzoyl chloride was not practicable, but addition of benzonitrile to 7 yielded 84% of the benzoylated product 14. Treatment of 7 with Me1 led to 15 (30%) along with 40% of 18, C-alkylation being accompanied by halogen-metal exchange. Prior addition of lithium 2-thienylcyanocuprate increased the yield of 15 to 50% and using dimethyl sulfate instead of Me1 led to 77% of 15. No a-u-anomers could be detected, except with ally1 bromide as the electrophile, which yielded in a 1:l mixture of the anomers 16 and 17.

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Cyclit‐Reaktionen, V. Synthese von enantiomerenreinem Valienamin aus Quebrachit

Cited by 61 publications

References 29 publications

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Host-specificity of uropathogenic Escherichia coli depends on differences in binding specificity to Gal alpha 1-4Gal-containing isoreceptors.

Preparation and Transmetallation of a Triphenylstannyl β‐D‐Glucopyranoside: A highly stereoselective route to β‐D‐C‐glycosides via glycosyl dianions

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