E
Synlett
M. Samarasimhareddy et al.
Letter
(
7) (a) Groneberg, R. D.; Miyazaki, T.; Stylianides, N. A.; Schulze, T.
Briefly, oNBC-Cl (10.32 mmol) was added dropwise to a stirred
solution of phenyl 3,4,6-trihydroxy-2-deoxy-2-azido-1-seleno-
β-D-galactopyranoside and DMAP (12.9 mmol) was dissolved in
anhyd DMF (10 mL) at 0 °C. The reaction was allowed to stir at
rt for 12 h. The reaction was quenched with ice and the crude
oNBC-protected phenyl 3,4,6-tri-O-oNBC-2-deoxy-2-azido-1-
seleno-β-D-galactopyranoside was isolated into EtOAc (2 × 15
J.; Stahl, W.; Schreiner, E. P.; Suzuki, T.; Iwabuchi, Y.; Smith, A.
L.; Nicolaou, K. C. J. Am. Chem. Soc. 1993, 115, 7593. (b) Nicolaou,
K. C.; Hummel, C. W.; Nakada, M.; Shibayama, K.; Pitsinos, E. N.;
Saimoto, H.; Mizuno, Y.; Baldenius, K. U.; Smith, A. L. J. Am.
Chem. Soc. 1993, 115, 7625. (c) Watanabe, S.; Sueyoshi, T.;
Ichihara, M.; Uehara, C.; Iwamura, M. Org. Lett. 2001, 3, 255.
8) Xiao, P.; Zhang, J.; Dumur, F.; Tehfe, M. A.; Morlet-Savary, F.;
Graff, B.; Gigmes, D.; Fouassier, J. P.; Lalevée, J. Prog. Polym. Sci.
(
(
mL). The combined organic layer was washed with H O (15 mL)
2
and brine (10 mL) and the solvent was evaporated. The crude
product was purified using silica column chromatography (15%
EtOAc in hexane) to afford the pure compound 9 (white solid,
2
015, 41, 32.
9) (a) Amit, B.; Zehavi, U.; Patchornik, A. J. Org. Chem. 1974, 39,
92. (b) Sebej, P.; Solomek, T.; Hroudna, L.; Brancova, P.; Klan, P.
1
overall yield: 38%).
1
J. Org. Chem. 2009, 74, 8647. (c) Solomek, T.; Mercier, S.; Bally,
T.; Bochet, C. G. Photochem. Photobio. Sci. 2012, 11, 548.
H NMR (CDCl ): δ = 8.09–8.15 (m, 3 H), 7.57–7.67 (m, 8 H),
3
7.42–7.53 (m, 3 H), 7.27–7.30 (m, 3 H), 6.01–6.02 (d, J = 5.4 Hz,
1 H, H1), 5.57–5.67 (m, 4 H), 5.54–5.55 (d, J = 6.8 Hz, 2 H), 5.46–
5.47 (m, 1 H, H4), 4.98–5.01 (dd, J = 3.2, 10.8 Hz, 1 H, H3), 4.76–
4.78 (t, J = 6.5 Hz, 1 H, H5), 4.36–4.39 (dd, J = 5.5, 10.8 Hz, 1 H,
H2), 4.28–4.32 (m, 1 H, H6′), 4.20–4.23 (m, 1 H, H6). 13C NMR
(d) Bochet, C. G. J. Chem. Soc., Perkin Trans. 1 2002, 125.
(
10) (a) Zhang, Y.; Yin, Q.; Yin, L.; Ma, L.; Tang, L.; Cheng, J. Angew.
Chem. Int. Ed. 2013, 52, 6435. (b) Morere, A.; Mouffouk, F.;
Leiris, S.; Leydet, A.; Montero, J. L. J. Carbohydr. Chem. 2006, 25,
451. (c) Eller, S.; Collot, M.; Yin, J.; Hahm, H. S.; Seeberger, P. H.
(125 MHz, CDCl ): δ = 154.3, 154.2, 153.3, 147.1, 146.9, 146.8,
3
Angew. Chem. Int. Ed. 2013, 52, 5858. (d) Komarova, B. S.;
Maryasina, S. S.; Tsvetkov, Y. E.; Nifantiev, N. E. Synthesis 2013,
135.0, 134.1, 134.0, 134.0, 131.1, 129.3, 129.0, 128.9, 128.8,
128.7, 128.4, 128.1, 126.9, 125.1, 83.8, 75.0, 70.9, 68.4, 66.8,
66.8, 66.3, 64.8, 58.5. MS (ESI): m/z [M + Na] calcd for
+
45, 471.
(
11) oNBC Removal and Workup Procedure for Compound 6: A
oNBC-protected maltose 6 (10 mg) derivative was dissolved in a
MeCN–TDW (1.5 mL, 70:30) mixture. The solution was trans-
ferred into a quartz cuvette equipped with a small magnetic
stirrer. The LED lamp was set to pass the beam directly into the
solution of the cuvette. The sample was irradiated at 365 nm in
a dark room with uniform magnetic stirring. The solution
slowly starts to turn brown indicating the removal of the oNBC
groups. The complete removal of the protecting groups was
C36H30N O16SeNa: 905.08; found: 904.11.
6
(14) Synthesis of Azido-1-O-allyl-2-deoxy-3,4,6-tri-O-oNBC-D-
galactopyranoside 7: To a stirred solution of 9 (50 mg, 0.056
mmol) in anhyd CH Cl (1.5 mL) 4 Å powdered molecular sieves
2
2
were added and the mixture was stirred for 1 h at rt under an
argon atmosphere. Allyl alcohol (0.680 mmol, 46 μL) and N-
iodosuccinimide (19.1 mg, 0.085 mmol) were added sub-
sequently under argon and the reaction mixture was cooled to
0 °C. Then the reaction mixture was treated with trifluoro-
methanesulfonic acid (0.030 mmol, 3 μL) and stirred at 0 °C for
4 h. The progress of the reaction was monitored by TLC. After
completion of the reaction, the mixture was quenched with TEA
(30 μL) and treated with sat. sodium thiosulfate. Then the
mixture was diluted with CH Cl (10 mL) and filtered. The fil-
1
monitored by either TLC, or RP-HPLC or H NMR. It took around
9
h of the irradiation time to completely remove all the eight
oNBC groups.
Workup Procedure: After complete removal of all the eight
oNBC groups, the reaction mixture was transferred into a 15-
mL conical centrifuge tube and lyophilized. The lyophilized
crude maltose was triturated with Et O (2 mL), CH Cl (1.5 mL)
2
2
trate was washed with H O (2 × 10 mL), brine (10 mL). The
2
organic layer was dried over Na SO . After evaporation of the
2
2
2
2
4
and dried under vacuum. Maltose with natural anomeric ratio
NMR confirmation) was obtained with a yield of 58%. The pure
unprotected maltose was obtained without any chromato-
graphic purification.
solvent, the crude solid material was purified by column chro-
matography (15% EtOAc–hexane) to afford 7 (28 mg, 64%) as a
white solid.
(
Compound 7: isolated as a mixture of isomers and was used as
(
12) (a) Zhang, Z. Y.; Ollmann, I. R.; Ye, X. S.; Wischnat, R.; Baasov, T.;
Wong, C. H. J. Am. Chem. Soc. 1999, 121, 734. (b) Guillemineau,
M.; Auzanneau, F. I. J. Org. Chem. 2012, 77, 8864.
such for the removal of oNBC protecting groups; 28 mg (64%
1
yield); white solid. H NMR (CDCl ): δ = 8.10–8.15 (m, 3 H),
3
7.63–7.68 (m, 4 H), 7.56–7.60 (m, 2 H), 7.43–7.53 (m, 3 H),
5.88–5.99 (m, 1 H), 5.56–5.69 (m, 6 H), 5.44–5.45 (d, J = 4.3 Hz,
1 H), 5.383–5.389 (m, 1 H), 5.33–5.35 (m, 1 H), 5.26–5.29 (m, 2
H), 5.10–5.11 (d, J = 3.8 Hz, 0.5 H, H1α), 4.65–4.69 (dd, J = 7.6,
14.2 Hz, 1 H), 4.47–4.49 (d, J = 5.8 Hz, 0.5 H, H1β), 4.42–4.46 (m,
1 H), 4.36–4.40 (m, 1 H), 4.17–4.26 (m, 1 H), 4.08–4.12 (m, 1 H),
(
13) Synthesis of Phenyl 3,4,6-Tri-O-oNBC-2-deoxy-2-azido-1-
seleno-β-D-galactopyranoside 9: To a solution of phenyl 3,4,6-
tri-O-acetyl-2-deoxy-2-azido-1-seleno-β-D-galactopyranoside
(500 mg, 1.1 mmol) dissolved in MeOH (5 mL) was added
NaOMe (20 mg, 0.37 mmol) dissolved in MeOH (5 mL) at rt.
After the reaction went to completion [monitored by TLC
13
3.92–3.95 (m, 1 H), 3.81–3.86 (m, 1 H). C NMR (125 MHz,
(
EtOAc–hexane, 1:1)] the reaction was quenched with Amber-
CDCl ): δ = 154.4, 154.3, 153.5, 153.4, 147.4, 134.3, 134.3,
134.27, 134.1, 134.1, 133.5, 133.3, 130.7, 129.6, 129.5, 129.5,
129.5, 129.3, 129.2, 128.6, 128.5, 128.5, 125.0, 100.5, 96.7, 74.9,
3
+
lite-120-H , filtered and washed with MeOH. The solvent was
evaporated to obtain the phenyl 3,4,6-trihydroxy-2-deoxy-2-
azido-1-seleno-β-D-galactopyranoside. The crude phenyl 3,4,6-
trihydroxy-2-deoxy-2-azido-1-seleno-β-D-galactopyranoside
was protected with oNBC-Cl without any further purification.
72.5, 71.9, 70.9, 70.1, 69.8, 68.6, 66.6, 66.3, 66.1, 65.4, 65.2, 60.6,
+
57.4. MS (ESI): m/z [M + Na] calcd for C33H30N O17Na: 805.16;
6
found: 805.17.
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2018, 29, A–E