F. W. Lichtenthaler, M. Oberthür, S. Peters,
FULL PAPER
HЈ), 3.83Ϫ4.18 (m, 8 H, 4 All-1-H2), 4.41 (d, 1 H, 4a-H), 4.62 (d, (m, 6 H, 1b-H, 2b-H, 2 All-3-H2), 5.35 (dd, 1 H, 2a-H); J1a,2a
1 H, 1a-H), 5.02 (m, 2 H, 1b-H, 2b-H), 5.11Ϫ5.30 (m, 9 H, 2a-H,
7.9, J2a,3a ϭ 10.2, J3a,4a ϭ2.3 Hz. Ϫ 13C NMR (75.5 MHz, CDCl3):
4 All-3-H2), 5.42 (d, 1 H, 4b-H); J1a,2a ϭ 10.0, J3a,4a ϭ 2.3, J5a,6a ϭ δ ϭ 55.6 (OCH3), 66.6 (C-4b), 67.5 (C-4a), 69.1, 69.8 (C-6a, C-6b),
5.9, J3b,4b ϭ 2.7, J5b,6b ϭ 6.2, J6b,6Јb ϭ Ϫ9.4 Hz. Ϫ 13C NMR
70.3 (C-2a), 70.7 (C-2b), 70.9, 71.1 (2 All-C-1), 73.6 (C-5b), 73.8
(75.5 MHz, CDCl3): δ ϭ 21.0 (AcCH3), 67.0 (C-4b), 68.5 (C-6b), (2 CH2Ph), 74.4 (C-5a), 78.6 (C-3b), 80.4 (C-3a), 98.8 (C-1b), 101.1
68.6 (C-4a), 69.1 (C-2a), 69.4 (C-6a), 70.7 (C-2b), 70.9, 71.2 (2 All-
(C-1a). Ϫ MS (FD): m/z ϭ 877 [Mϩ]. Ϫ C49H64O14 (877.04): calcd.
ϭ
C-1), 72.6 (C-5b, 2 All-C-1), 77.0 (C-3b), 77.9 (C-5a), 81.3 (C-3a), C 67.10, H 7.35; found C 67.01, H 7.24.
87.9 (C-1a), 99.5 (C-1b); JC1a-H ϭ 157.2, JC1b-H ϭ 163.8 Hz. Ϫ MS
5. β(1Ǟ4)-Galactotriosides
(FD): m/z ϭ 805 [Mϩ]. Ϫ C42H60O13S (804.99): calcd. C 62.67, H
7.51; found C 62.63, H 7.38.
4-Methoxyphenyl (4-O-Acetyl-3,6-di-O-allyl-2-O-pivaloyl-β-D-
galactopyranosyl)-(1Ǟ4)-(3,6-di-O-allyl-2-O-pivaloyl-β-
D-galacto-
Phenyl 4-O-(4-O-Acetyl-3-O-allyl-6-O-benzyl-2-O-pivaloyl-β-
galactopyranosyl)-3-O-allyl-6-O-benzyl-2-O-pivaloyl-1-thio-β-
D
D
-
-
pyranosyl)-(1Ǟ4)-3,6-di-O-allyl-2-O-pivaloyl-β- -galactopyranoside
D
(70): Thiogalactoside 51 (760 mg, 1.6 mmol) and 4-OH-free galac-
tobioside 62 (620 mg, 0.8 mmol) were coupled according to general
procedure A. Column chromatography (toluene/EtOAc, 6:1) af-
forded trisaccharide 70 (715 mg, 78%) as a syrup; Rf ϭ 0.41 (tolu-
ene/EtOAc, 4:1); [α]2D0 ϭ Ϫ4.8 (c ϭ 1.0, CHCl3). Ϫ 1H NMR
(300 MHz, CDCl3): δ ϭ 2.12 (s, 3 H, AcCH3), 3.47 (m, 5 H, 3-H
(aϪc), 6c-H2], 3.54 (t, J5,6 ϭ 6.2 Hz, 1-H, 5-H) 3.58Ϫ3.72 (m, 5 H,
two 5-H, 6a,b-H2), 3.75 (s, 3 H, OCH3), 3.83Ϫ4.20 (m, 12 H, 6
All-1-H2), 4.33 (d, 1 H, 4a-H), 4.39 (d, 1 H, 4b-H), 4.75 (d, 1 H,
1a-H), 4.98 (d, 1 H, 1b-H), 5.01 (dd, 1 H, 2b-H), 5.04 (dd, 1 H,
2c-H), 5.07 (d, 1 H, 1c-H), 5.12Ϫ5.35 (m, 12 H, 6 All-3-H2), 5.33
(m, 1 H, 2a-H), 5.42 (d, 1 H, 4c-H); J1a,2a ϭ 7.8, J3a,4a ϭ 2.5,
J1b,2b ϭ 7.8, J2b,3b ϭ 9.4, J3b,4b ϭ 2.6, J1c,2c ϭ 7.9, J2c,3c ϭ 9.8,
J3c,4c ϭ 3.0 Hz. Ϫ 13C NMR (75.5 MHz, CDCl3): δ ϭ 20.8
(AcCH3), 55.6 (OCH3), 66.9 (C-4c), 67.9 (C-4b), 68.3 (C-4a), 68.4
(C-6c), 69.1 (C-6a), 69.8 (C-6b), 70.4, 70.6, 70.8 [C-2 (aϪc)], 70.9,
71.0, 71.1, 72.5 (6 All-C-1), 72.4 (C-5c), 73.7 (C-5b), 74.6 (C-5a),
76.9 (C-3c), 80.1, 80.3 (C-3a,b), 99.2 (C-1c), 99.5 (C-1b), 101.1 (C-
1a); JC-1a,H ϭ 160.2, JC-1b,H ϭ 165.4, JC-1c,H ϭ 166.6 Hz. Ϫ MS
(FD): m/z ϭ 1145 [Mϩ]. Ϫ C60H88O21 (1145.34): calcd. C 62.92, H
7.74; found C 62.83, H 7.77.
galactopyranoside (61): The pMP galactobioside 56 (2.3 g,
2.5 mmol) was thiated as described above for 55 Ǟ 60. Column
chromatography of the resulting residue (toluene/EtOAc, 17:1)
yielded thiogalactobioside 61 (2.13 g, 94%) as a syrup; Rf ϭ 0.60
1
(toluene/EtOAc, 4:1); [α]2D0 ϭ Ϫ8.3 (c ϭ 1.0, CHCl3). Ϫ H NMR
(300 MHz, CDCl3): δ ϭ 2.00 (s, 3 H, AcCH3), 3.44Ϫ3.55 (m, 4 H,
3a-H, 3b-H, 6b-H2), 3.66 (t, 1 H, 5a-H), 3.71 (t, 1 H, 5b-H), 3.76
(m, 2 H, 6a-H2), 3.83Ϫ3.96, 4.09Ϫ4.15 (2 m, 4 H, 2 All-1-H2), 4.45
(dd, 2 H, CH2Ph), 4.46 (d, 1 H, 4a-H), 4.56 (s, 2 H, CH2Ph), 4.65
(d, 1 H, 1a-H), 5.05 (m, 2 H, 1b-H, 2b-H), 5.10Ϫ5.25 (m, 5 H, 2a-
H, 2 All-3-H2), 5.48 (d, 1 H, 4b-H); J1a,2a ϭ 10.0, J3a,4a ϭ 2.2,
J5,6 ϭ 6.0, J1b,2b ϭ 8.0, J3b,4b ϭ2.8, J5,6 ϭ 6.5 Hz. Ϫ 13C NMR
(75.5 MHz, CDCl3): δ ϭ 20.8 (AcCH3), 66.8 (C-4b), 68.2 (C-6b),
68.4 (C-4a), 69.0 (C-2a), 69.7 (C-6a), 70.7 (C-2b), 70.8, 71.1 (2 All-
C-1), 72.4 (C-5b), 73.7, 73.8 (2 CH2Ph), 76.9 (C-3b), 77.7 (C-5a),
81.3 (C-3a), 87.8 (C-1a), 99.4 (C-1b). Ϫ MS (FD): m/z ϭ 927 [(M
ϩ Na)ϩ]. Ϫ C50H64O13S (905.11): calcd. C 66.35, H 7.13; found C
66.22, H 7.09.
4-Methoxyphenyl 3,6-Di-O-allyl-4-O-(3,6-di-O-allyl-2-O-pivaloyl-β-
D-galactopyranosyl)-2-O-pivaloyl-β-D-galactopyranoside (62): Gal-
actobioside 55 (2.30 g, 2.8 mmol) was dissolved in CH2Cl2 (4 mL)
and MeOH (16 mL) and treated with NaOMe (0.5 in MeOH,
1.4 mL, 0.7 mmol). After stirring for 15 h at room temperature, the
solution was neutralized with acidic ion-exchange resin (Amberlite
IR 120) and concentrated. The residue was subjected to column
chromatography (toluene/EtOAc, 4:1) to yield 1.83 g (84%) of ga-
lactobioside acceptor 62 as a colourless syrup; Rf ϭ 0.51 (toluene/
EtOAc, 4:1); [α]2D0 ϭ Ϫ15.5 (c ϭ 1.0, CHCl3). Ϫ 1H NMR
(300 MHz, CDCl3): δ ϭ 2.35 (br. s, 1 H, 4b-OH), 3.50 (m, 2 H,
3a-H, 3b-H), 3.58 (m, 1 H, 5a-H), 3.65Ϫ3.78 (m, 5 H, 5b-H, 6a-
H2, 6b-H2), 3.75 (s, 3 H, OCH3), 3.94Ϫ4.25 (m, 8 H, 4 All-1-H2),
4.03 (m, 1 H, 4b-H), 4.44 (d, 1 H, 4a-H), 4.77 (d, 1 H, 1a-H), 5.08
(m, 2 H, 1b-H, 2b-H), 5.13Ϫ5.32 (m, 8 H, 4 All-3-H2), 5.34 (dd, 1
H, 2a-H); J1a,2a ϭ 7.9, J2a,3a ϭ 10.3, J3a,4a ϭ 2.5 Hz. Ϫ 13C NMR
(75.5 MHz, CDCl3): δ ϭ 55.6 (OCH3), 66.4 (C-4b), 67.6 (C-4a),
68.9, 69.4 (C-6a, C-6b), 70.3 (C-2a),70.6 (C-2b), 70.9, 71.0, 72.5,
72.6 (4 All-C-1), 73.5 (C-5b), 74.4 (C-5a), 78.6 (C-3b), 80.3 (C-3a),
99.8 (C-1b), 101.1 (C-1a). Ϫ MS (FD): m/z ϭ 777 [(M ϩ H)ϩ]. Ϫ
C41H60O14 (776.92): calcd. C 63.38, H 7.78; found C 63.09, H 7.65.
4-Methoxyphenyl (3,6-Di-O-allyl-2-O-pivaloyl-β-
yl)-(1Ǟ4)-(3,6-di-O-allyl-2-O-pivaloyl-β- -galactopyranosyl)-
(1Ǟ4)-3,6-di-O-allyl-2-O-pivaloyl-β- -galactopyranoside (71): A so-
D-galactopyranos-
D
D
lution of galactotrioside 70 (420 mg, 0.37 mmol) and NaOMe
(0.15 mL, 0.5 in MeOH) in MeOH (3 mL) was stirred at room
temperature for 16 h, followed by neutralisation with Amberlite IR
120 (Hϩ form) and removal of the solvent in vacuo. Purification
of the residue by elution from a silica gel column (toluene/EtOAc,
4:1) afforded 71 (330 mg, 81%) as a colourless syrup; Rf ϭ 0.48
1
(toluene/EtOAc, 2:1); [α]2D0ϭ Ϫ17.0 (c ϭ 1.0, CHCl3). Ϫ H NMR
(300 MHz, CDCl3): δ ϭ 2.10Ϫ2.40 (b, 1 H, 4c-OH), 3.42Ϫ3.48 [m,
3 H, 3-H (aϪc)], 3.49Ϫ3.77 [m, 9 H, 5-H (aϪc), 6-H2 (aϪc)], 3.74
(s, 3 H, OCH3), 3.92Ϫ4.21 (m, 12 H, 6 All-1-H2), 4.02 (m, 1 H, 4c-
H), 4.34 (d, 1 H, 4a-H), 4.38 (bd, 1 H, 4b-H), 4.74 (d, 1 H, 1a-H),
4.96Ϫ5.09 (m, 4 H, 1b,c-H, 2b,c-H), 5.12Ϫ5.34 (m, 12 H, 6 All-3-
H2), 5.29 (m, 1 H, 2a-H); J1a,2a ϭ 7.9, J3a,4a ϭ 2.6, J3b,4b ϭ 2.1 Hz.
Ϫ
13C NMR (75.5 MHz, CDCl3): δ ϭ 55.8 (OCH3), 66.7, 68.2, 68.6
[C-4 (aϪc)], 69.2, 69.8, 70.1 [C-6 (aϪc)], 70.6, 70.7, 71.1 [C-2
(aϪc)], 71.2, 71.2, 71.3, 72.7 (6 All-C-1), 73.7, 74.2, 74.8 [C-5
(aϪc)], 79.1, 80.4, 80.6 [C-3 (aϪc)], 99.3, 99.7 (C-1b,c), 101.3 (C-
1a). Ϫ MS (ESI): m/z ϭ 1125.8 [(M ϩ Na)ϩ]. Ϫ C58H86O20
(1103.31): calcd. C 63.14, H 7.86; found C 62.98, H 7.99.
4-Methoxyphenyl 3-O-Allyl-4-O-(3-O-allyl-6-O-benzyl-2-O-pival-
oyl-β-D-galactopyranosyl)-6-O-benzyl-2-O-pivaloyl-β-D-galacto-
pyranoside (63): Galactobioside 56 (2.30 g, 2.5 mmol) was de-O-
acetylated with NaOMe/MeOH as described above for 55 Ǟ 62.
Column chromatography (toluene/EtOAc, 6:1) of the residue gave 4-Methoxyphenyl (3,6-Di-O-allyl-β-
the 4-OH free analogue 63 (1.86 g, 85%) as a yellow syrup; Rf ϭ di-O-allyl-β- -galactopyranosyl)-(1Ǟ4)-3,6-di-O-allyl-β-
pyranoside (72): LiOH·H2O (570 mg, 13.6 mmol) was added to a
D-galactopyranosyl)-(1Ǟ4)-(3,6-
D
D-galacto-
1
0.44 (toluene/EtOAc, 4:1); [α]2D0 ϭ Ϫ17.4 (c ϭ 1.0, CHCl3). Ϫ H
NMR (300 MHz, CDCl3): δ ϭ 3.49 (m, 2 H, 3a-H, 3b-H), 3.60 solution of trisaccharide 70 (390 mg, 0.34 mmol) in MeOH
(m, 1 H, 5a-H) 3.67Ϫ3.83 (m, 8 H, 5b-H, 6a-H2, 6b-H2, OCH3), (15 mL). After refluxing for 16 h, the mixture was filtered, the fil-
3.87Ϫ4.19 (m, 4 H, 2 All-1-H2), 4.04 (br. s, 1 H, 4b-H), 4.46 (d, 1 trate was neutralised with an acidic ion-exchange resin (Amberlite
H, 4a-H), 4.49 (m, 4 H, 2 CH2Ph), 4.77 (d, 1 H, 1a-H), 5.08Ϫ5.29
IR 120), and taken to dryness in vacuo. Chromatography (toluene/
3864
Eur. J. Org. Chem. 2001, 3849Ϫ3869