B. Holm et al. / Bioorg. Med. Chem. 11 (2003) 3981–3987
3985
2,3,6-tri-O-Acetyl-4-O-methyl-ꢀ-D-galactopyranosyl bro-
mide (2a) and 2,3,6-tri-O-acetyl-4-deoxy-4-fluoro-ꢀ-D-
galactopyranosyl bromide (2b). Bromosugars 2a and 2b
were prepared by treatment of the corresponding 1-O-
acetyl sugars 1a and 1b with 15% HBr in HOAc/Ac2O
(6:1) for 2–3 h at room temperature. The solutions were
diluted with CH2Cl2 and washed with water, saturated
aqueous NaHCO3 and water, dried (Na2SO4), filtered
and concentrated. Bromosugar 2a was used without
further purification whereas 2b was purified by flash
added dropwise to an ice-cold stirred mixture of
Fmoc-Hyl(Cbz)-OAllyl (50 mg, 0.09 mmol), silver sili-
cate (135 mg) and crushed 3 A molecular sieves
(100 mg) in dry toluene/CH2Cl2 (1:3, 4 mL) under N2 in
the absence of light. After stirring for 5.5 h the solid
material was filtered off (Hyflo supercel) and washed
with CH2Cl2 (5 mL) and the combined filtrates were
concentrated. Flash column chromatography of the
residue (toluene/MeCN 100:1!6:1) gave 3b (50 mg,
20
ꢁ
1
0.059 mmol, 66%): ½ꢀ 5 (c 0.44, CHCl3); H NMR
D
column
chromatography
(heptane/ethyl
acetate
(CDCl3) d 5.88–5.79 (m, 1H, OCH2CH¼CH2), 5.47–
5.42 (m, 1H, NH-e), 5.32 (d, 1H, J=7.2 Hz, NH-a), 5.27
(d, 1H, J=17.1 Hz, OCH2CH¼CH2trans), 5.20 (d, 1H,
J=10.4 Hz, OCH2CH¼CH2cis), 5.15 (dd, 1H, J=10.4,
8.1Hz), 5.05, and 5.01 (2 ABd, each 1H, J=12.3 Hz,
OCH2Ph), 4.83 (ddd, 1H, J=14.3, 8.0, 2.5 Hz, H-3), 4.72
(dd, 1H, J=50.2, 2.6 Hz, H-4), 4.58 (d, 2H, J=4.6 Hz,
OCH2CH¼CH2), 4.45–4.24 (m, 4H, NHðCOÞOCH2CH,
H-1, H-a), 4.22–4.12 (m, 3H, NHðCOÞOCH2CH, H-6,6),
3.72–3.55 (m, 2H, H-d, H-5), 3.38–3.30 (m, 1H, H-e),
3.15–3.07 (m, 1H, H-e), 2.03 (s, 3H, OAc), 1.94 (s, 6H, 2
OAc), 1.70–1.40 (m, 3H, H-b, H-g,g); 13C NMR (CDCl3)
d 170.2, 169.1, 156.7, 143.8, 143.6, 141.3, 136.5, 131.3,
128.5, 127.0, 125.0, 120.0, 119.3, 101.0, 86.6, 84.8, 80.7,
71.3, 71.1, 70.9, 68.7, 67.0, 66.7, 66.2, 61.5, 53.6, 47.1,
44.8, 29.6, 28.6, 28.4, 20.6; HRMS (FAB): calcd for
C44H49FN2NaO14 871.3066 (M+Na), found 871.3086.
19:1!4:1). 1H NMR (CDCl3) 2a: d 6.68 (d, 1H,
J=3.9 Hz, H-1), 5.32 (dd, 1H, J=10.6, 2.9 Hz, H-3),
5.14 (dd, 1H, J=10.6, 3.8 Hz, H-2), 4.31–4.13 (m, 3H,
H-5, H-6,60), 3.81 (d, 1H, J=2.9 Hz, H-4), 3.50 (s, 3H,
OCH3), 2.12, 2.09, and 2.09 (3s, each 3H, OAc); 2b: d
6.70 (d, 1H, J=4.0 Hz, H-1), 5.34 (ddd, 1H, J=26.7,
10.8, 2.5 Hz, H-3), 5.12 (dd, 1H, J=10.4, 3.9 Hz, H-2),
5.00 (dd, 1H, J=50.1, 2.9 Hz, H-4), 4.44–4.26 (m, 3H,
H-5, H-6,60), 2.16, 2.12, and 2.11 (3s, each 3H, OAc).
(5R)-Nꢀ-(Fluoren-9-yl-methoxycarbonyl)-N"-benzyloxy-
carbonyl-5-O-(2,3,6-tri-O-acetyl-4-O-methyl-ꢁ-D-galac-
topyranosyl)-5-hydroxy-L-lysine allyl ester (3a).
A
solution of O-methylated galactosyl bromide 2a
(141 mg, 0.38 mmol) in dry CH2Cl2 (2mL) was added
dropwise to an ice-cold stirred mixture of Fmoc-Hyl(Cbz)-
OAllyl (142 mg, 0.26 mmol), silver silicate (384 mg) and
crushed 3 A molecular sieves (142 mg) in dry CH2Cl2
(4 mL) under N2 in the absence of light. After stirring
for 3 h additional 2a (50 mg) in CH2Cl2 (0.5 mL) was
added, the mixture was stirred for a further 2 h and was
then allowed to attain room temperature. The solid
material was filtered off (Hyflo supercel) and washed
with CH2Cl2 and the combined filtrates were con-
centrated. Flash column chromatography of the residue
(5R)-Nꢀ-(Fluoren-9-yl-methoxycarbonyl)-N"-benzyloxy-
carbonyl-5-O-(2,3,6-tri-O-acetyl-4-O-methyl-ꢁ-D-galac-
topyranosyl)-5-hydroxy-L-lysine
(4a).
(PPh3)4Pd(0)
(18 mg, 15 mmol) was added to a stirred solution of 3a
(124 mg, 0.144 mmol) and morpholine (38 mL,
0.43 mmol) in dry THF under N2 with protection from
light. After stirring at room temperature for 35 min the
solution was diluted with EtOAc (50 mL), washed with
1 M aqueous KHSO4 and brine, dried (Na2SO4), filtered
and concentrated. Flash column chromatography of the
(toluene/MeCN 5:1) gave 3a (137 mg, 0.159 mmol, 60%):
20
D
½ꢀ 0ꢁ (c 1, CHCl3); 1H NMR (CDCl3) d 5.97–5.80 (m,
1H, OCH2CH¼CH2), 5.64 (t, 1H, J=5.2 Hz, NH-e),
5.45 (d, 1H, J=8.1 Hz, NH-a), 5.33 (d, 1H, J=17.1 Hz,
OCH2CH¼CH2trans), 5.28–5.20 (m, 2H, H-2,
OCH2CH¼CH2cis), 5.11 (ABd, 1H, J=14.0 Hz,
OCH2Ph), 5.07 (ABd, 1H, J=14.0 Hz, OCH2Ph), 4.89
(dd, 1H, J=10.5, 3.0 Hz, H-3), 4.63 (d, 2H, J=5.0 Hz,
residue (toluene/EtOH 50:1!10:1!5:1) gave 4a (90 mg,
20
D
0.11 mmol, 76%): ½ꢀ 3ꢁ (c 1, CHCl3); 1H NMR
(CDCl3/MeOD 1:1) d 6.27 (t, 1H, J=4.9 Hz, NH-e), 5.16
(dd, 1H, J=10.4, 8.0 Hz, H-2), 5.05 (s, 2H, OCH2Ph),
4.96 (dd, 1H, J=10.4, 2.8 Hz, H-3), 4.48 (d, 1H,
J=7.9 Hz, H-1), 4.39–4.30 (m, 2H, NHðCOÞOCH2CH),
4.22–4.11 (m, 4H, NHðCOÞOCH2CH, H-6, H-6, H-a),
3.71 (t, 1H, J=6.1 Hz, H-5), 3.67–3.59 (m, 2H, H-4, H-
d), 3.48 (s, 3H, OCH3), 3.36–3.25 (m, 1H, H-e), 3.18–3.09
(m, 1H, H-e), 2.05, 1.99 and 1.98 (3s, each 3H, OAc),
2.01–1.85 (m, 1H, H-b), 1.70–1.49 (m, 3H, H-b, H-g,g);
13C NMR (CDCl3/MeOD 1:1) d 174.7, 171.6, 171.2,
170.8, 157.9, 157.6, 144.5, 144.4, 141.9, 137.2, 129.0,
128.6, 128.5, 128.2, 127.6, 125.6, 120.4, 101.8, 81.3, 77.0,
74.4, 72.7, 70.4, 67.4, 67.2, 63.0, 61.8, 54.3, 47.7, 45.5,
29.7, 28.4, 20.9, 20.8; HRMS (FAB): calcd for
C42H48N2NaO15 843.2905 (M+Na), found 843.2946.
OCH2CH¼CH),
4.48–4.28
H-a),
(m,
4.28–4.17
4H,
(m,
H-1,
3H,
NHðCOÞOCH2CH,
NHðCOÞOCH2CH, H-6,6), 3.67 (t, 1H, J=6.3 Hz, H-5),
3.71–3.58 (m, 2H, H-4, H-d), 3.49 (s, 3H, OCH3), 3.45–
3.36 (m, 1H, H-e), 3.21–3.11 (m, 1H, H-e), 2.08, 1.99, and
1.99 (3s, each 3H, OAc), 2.02–1.90 (m, 1H, H-b), 1.75–
1.36 (m, 3H, H-b, H-g,g); 13C NMR (CDCl3) d 171.7,
170.4, 170.3, 169.2, 156.7, 156.9, 143.9, 143.8, 141.2,
136.5, 131.3, 128.4, 128.2, 128.0, 127.9, 127.7, 127.0,
127.0, 125.0, 119.9, 119.2, 101.3, 80.8, 76.2, 73.7, 72.2,
69.4, 66.9, 66.6, 66.1, 62.3, 61.4, 53.7, 47.1, 44.8, 28.7,
28.3, 20.7, 20.6, 20.6; HRMS (FAB): calcd for
C45H52N2NaO15 883.3265 (M+Na), found 883.3268.
(5R)-Nꢀ-(Fluoren-9-yl-methoxycarbonyl)-N"-benzyloxy-
carbonyl-5-O-(2,3,6-tri-O-acetyl-4-deoxy-4-fluoro-ꢁ-D-
galactopyranosyl)-5-hydroxy-L-lysine (4b). Deallylation
and workup of 3b (50 mg) as described for the prepara-
tion of 4a followed by flash column chromatography
(5R)-Nꢀ-(Fluoren-9-yl-methoxycarbonyl)-N"-benzyloxy-
carbonyl-5-O-(2,3,6-tri-O-acetyl-4-deoxy-4-fluoro-ꢁ-D-
galactopyranosyl)-5-hydroxy-L-lysine allyl ester (3b). A
solution of fluorinated galactosyl bromide 2b (50 mg,
0.135 mmol) in dry toluene/CH2Cl2 (1:1, 1.5 mL) was
(CHCl3/MeOH 100:1!20:1) gave 4b (39 mg, 82%):
20
½ꢀ 9ꢁ (c 1.2, CHCl3); 1H NMR (CDCl3) d 5.77 (d, 1H,
D