A novel, reductive ring-opening of carbohydrate benzylidene acetals, with unusual regioselectivity

Garegg, Per J.; Hultberg, Hans

doi:10.1016/s0008-6215(00)80766-1

Cited by 246 publications

(114 citation statements)

References 11 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…Reductive cleavage (9) of methyl 2-acetamido-3-0-benzyl-4,6-0-benzylidene-2-deoxy-P-D-glucopyranoside (18) provided 39, which was condensed with bromide 40 (19) under Helferich conditions (66% yield). This product was deacetylated to produce 42.…”

Section: P-d-g~i-(i+~)-p-d-g~cnac-om~mentioning

confidence: 99%

“…calcd. for C4,H5,NOlo: C 69.62,H 6.93 4.5 1 (d,overlapped,Jla,2a 8.5 Hz, H-la), 4.37 (overlapped, H-5c), 4.24 (dd,IH,JZb,,b 9.0 HZ, H-2b), 4.17 (dd, lH, J3=,4, 8.0 HZ, JZa,)= 9.5 HZ, H-3a), 4.02 (dd, 1 H, J2c,3c 10.0 HZ, H -2~) , 3.97 (d, 1 H, J,b,,b 2.5 HZ, Jab.5b < 1 HZ, H-4b), 3.92 (dd, 1 H, J3c,4c 2.5 HZ, H-3c), 3.85 (bd, lH, H-4c), 3.44 (s,3H,CH,O), 3.06 (t, 1 H, J,,,,, 8.5 Hz, H-4a), 1.89 (s, 3H, CH,CO), 1.34 (d, 3H, J5a,6a 6.0 HZ, H3-6a), 1.20 (d,3H,J5c,6c 6.5 Hz,H,. Anal.…”

Section: Methyl 2-acetamido-3-0-(2-0-acetyi-346-tri-o-benzyl-~-~-gamentioning

confidence: 99%

“…calcd. for CS2HS7NOI3S: C 66.72,H 6.14,N 1.50;found: C 66.37,H 6.42,N 1.57. A minor compound (22 rng, 8.3%) was isolated on further elution of the column and identified as methyl 2-acetamido-4-0-(2-0-acety1,3,4,6- -3-0-pherzoxycarborzyl-@-glump 169-17 1°C (methanol-ether); [a],, -10 (c 0.2, chloroform); 'H nrnr (CDC1,) 6: 7.40;25H,5Ph), 5.8 1 (d,1 H,JNH.2,9.0 HZ, NH), 5.19 (dd,1H,Jlb,Zh 8.0 HZ,J2b,3b 10.0 HZ,, 4.90 (dd,IH,J3,,4,8.5 Hz,J2,,,,,10.0 Hz,, 4.31, 4.27 (2d, each lH, J 8.0 Hz, H-la, H-1 b), 4.00 (ddd, lH, H-2a), 3.88 (d,t,2H,J,,,,,and J,,,,;,8.5 Hz,, 3.36 (s,3H,CH,O), 3.30 (dd,…”

Section: Methyl 2-acetamido-26-dideoxy-3-0-[2-0-(a-~-fucopyranosyl)-mentioning

confidence: 99%

“…,,,,,,= J3aeq,2a 4.5 Hz,0.21 mmol) were added and heating was continued for 2 h. Evap-H-3aeq), 1.98 (s, 3H, CH,CO), 1.64 (td,IH,J,,,,,,,= JZn,,anx oration and recrystallization from dichloromethane-hexane af-1 1.5 Hz, H-3aax), 1.22 (d, 3H, H,-6c Table 3. chloroform); 'H nmr (CDCI,) 20H,4Ph), 6.80 (d,lH,JNH,>, 9.0 HZ, NH), 5.36 (dd,1H,Jlb.Zb 8.0 HZ,J2h.3h 2,4-Di-0-benzyl-3,6-dideoxy-~-xylo-hexopyrnnose (34) 10.0 Hz,, 4.92 (d,from ABq,I H,JA.B 12.0 HZ,lCHrPh), Methyl 2,4-di-0-benzyl-3,6-dideoxy-a-~-xylo-hexopyranoside 7H,CH2Ph), 4.36 (d,IH,J,;,,,2.0 Hz,, 4.26 (21) 3.96 (bd, 1~, J,,,,, 3.0 H~, trifluoroacetic acid and kept at room temperature for 16 h. sol-H-4b), 3.87 (m, overlapped, H-4a), 3.52 (overlapped, H-3b), …”

Section: Merlz~l2-acetamiclo-4-mentioning

confidence: 99%

“…For personal use only. J5.6 6.5 HZ,J,,,, 12.0 HZ, J*.s 2.0 HZ, H-5), 3.98 (ddd,lH,J3,* 5.0 HZ,J~,J~,12.0 HZ,J2,, 9.0 HZ, H-3), 3.4 (dd, 1 H, H-2), 2.13 (ddd,IH,J,,,,,,, 13.0 Hz, H-4eq), 1.48 (q, 1 H, H-4ax), 1.23 (d, 3H, H,-6).…”

Section: Merlz~l2-acetamiclo-4-mentioning

confidence: 99%

See 4 more Smart Citations

Molecular recognition XII. The binding of the H human blood group determinants and congeners by a lectin of Galactiatenuiflora

Cromer¹,

Spohr²,

Khare³

et al. 1992

Can. J. Chem.

View full text Add to dashboard Cite

70. 151 1 (1992).The H-type 2 human blood group-related trisaccharide (a-L-Fuc-(lcj2b)-P-D-Gal-(] b4a)-P-D-GlcNAc-OMe (52)) IS bound by the anti-H lectin of Galnctin tenuiflora very differently than by the lectin I of Ulex europaeus. The reason why the Galactia lectin binds the H-type 1 related trisaccharide (a-~-Fuc-(lc~2b)-~-~-Gal-(lb3a)-~-~-GlcNAc-OMe (5)) more strongly and methyl a-L-fucopyranoside much more weakly than does the U1e.r lectin is that, for the Galactia lectin, the hydroxyl groups at positions 3a, 3b, 4b, and 4c are indispensable to complex formation whereas it is the hydroxyl groups at positions 3b, 2c, 3c, and 4c which provide the key polar intractions in the case of the Ulex lectin. The H-type 2 (52). Galactia lectin complex appears to have the hydroxyl groups at positions 6b, 2c, and 3c at or near the periphery of the combining site and the three key hydroxyl groups hydrogen bonded to the protein deep within the combining site and sheltered from water. The CH'O-la, NHAc-2a, and CH,OH-6a groups likely remain in the aqueous phase remote from the surface of the protein.REMY CROMER, ULRIKE SPOHR, DEVESHWARI P. KHARE, JAQUES LEPENDU et RAYMOND U. LEMIEUX. Can. J. Chem. 70, 1511 (1992).On observe que la liaison entre le trisaccharide du groupe sanguin H-de type 2 (a-~-F~c-(Ic--t2b)-P-~-Gal-(lb+4a)-P-D-GlcNAc-OMe (52)) et la lectine anti-H de Galactia tenuiflora est trks differente de celle qui le lie 2 la lectine I de (5)) qui est plus forte -et la liaison avec l'a-L-fucopyranoside de mtthyle qui est beaucoup plus faible -que celles avec la lectine d'Ulex est que, pour la lectine de Galactia, les groupes hydroxyles aux positions 3a, 3b, 4b et 4c sont indispensables pour la formation de complexe alors que ce sont les groupes hydroxyles en positions 3b, 2c, 3c et 4c qui fournissent les interactions polaires cles dans le cas de la lectine d'Ule-r. Le complexe groupe H de type 2 (52). la lectine de Galactin semble possCder des groupes hydroxyles dans les positions 6b, 2c et 3c au niveau de, ou k la proximite de, la ptriphCrie du site de liaison alors que les trois groupes hydroxyles clCs sont lies par des ponts hydrogenes avec la prottine qui se trouve 2 l'interieur du site de liaison, protege de I'eau. 1'Ulex eziropaeus. La raison de la liaison entre la lectine de Galactia et le trisaccharide relie groupe H de type 1 (a-L- Fuc-(lc+2b)-P-~-Gal-(lb3a)-P-~-GlcNA~-OMeLes groupes CH,O-en la, NHAc-en 2a et Ch,OH-en 6a restent vraisemblablement dans la phase aqueuse qui se trouve CloignCe de la surface de la proteine.[Traduit par la rCdaction]

show abstract

Section: P-d-g~i-(i+~)-p-d-g~cnac-om~mentioning

confidence: 99%

Section: Methyl 2-acetamido-3-0-(2-0-acetyi-346-tri-o-benzyl-~-~-gamentioning

confidence: 99%