V. Zsoldos-Mády et al. / Carbohydrate Research 346 (2011) 1534–1540
1539
as white crystals (3.24 g, 66%), mp 156–158 °C; [
a
]
D
+3 (c 1.52,
H2O); mmax 1775 (shoulder), 1766 (lactone CO), 1653, 1555
H
(NHAc) cmꢀ1
.
N
N
N
N
N
N
Anal. Calcd for C7H11NO5: C, 44.44; H, 5.86; N, 7.40. Found: C,
44.65; H, 5.98; N, 7.42.
In accordance with NMR investigations, compound 12
remained unchanged for a week at rt and for a month at 0 °C in
D2O solution.
N
N
H
OAc
OAc
OAc
OAc
OAc
OAc
3.3.12. 2-Acetamido-2-deoxy-L-arabinono-1,4-lactone (13)
From compound 9, the lactone 13 was prepared by the proce-
dure described for the synthesis of 12, to furnish white crystals
17a
17b
Scheme 5. The pseudoaromatic chelate (17a) and the open phenylazo-phenylhyd-
razone forms (17b) of the peracetylated derivative.
of the recrystallized product in 65% yield, mp 155–157 °C; [a]
D
ꢀ3 (c 1.14, H2O). IR and NMR data are identical with those of com-
pound 12.
Anal. Calcd for C7H11NO5: C, 44.44; H, 5.86; N, 7.40. Found: C,
44.56; H, 5.90; N, 7.39.
(9:1) to give red needles (0.8 g), mp 181–182 °C. Anal. Calcd for
C
19H23N5O4: C, 59.20; H, 6.02; N, 18.17. Found: C, 59.63; H, 5.97;
N, 17.99.
(B) Compound 5 (1.0 g, 1.95 mmol) was treated with ethanol
3.3.13. 2-Acetamido-5-O-acetyl-2,3-dideoxy-D-glycero-pent-2-
enono-1,4-lactone (14)
(5 mL) and 25% aqueous ammonia (5 mL) and after 2 days the mix-
ture was worked up as described in procedure A, resulting red nee-
dles of 8 (0.54 g, 72%), mp 180–182 °C. 1H NMR spectra are
identical with those of the sample obtained by procedure A.
To a mixture of Ac2O (6 mL) and dry pyridine (10 mL) was
added 12 (2.0 g) and the mixture was allowed to stand at rt for
22 h. EtOAc (15 mL) and then diethyl ether (120 mL) were given
in portions to the solution to give white crystals. After filtration
and washing with ether–EtOAc (9:1) crude 14 (1.41 g, 62.5%) was
obtained, mp 154–156 °C. The product was purified by dissolving
in EtOAc (48 mL) and by adding ether (35 mL) then petroleum
ether (58 mL) to the solution. White crystals of 14 separated in
3.3.8. 2-Acetamido-2-deoxy-
(9)
L
-arabinose N,N0-diphenylformazan
Reaction of tetra-O-acetyl-
ous ammonia in ethanol was carried out as described for the prep-
aration of 8 to give the corresponding -enantiomer 9 in 74% yield,
L-arabinose formazan (7) with aque-
43.5% yield, mp 156–157 °C; [
a
]
+36 (c 1.56, EtOAc), lit.8 mp
D
L
153–154 °C; lit.8
[a]
D
+35.8 (c 0.7, EtOAc); mmax 1775 (shoulder),
mp 181–182 °C. Anal. Calcd for C19H23N5O4: C, 59.20; H, 6.02; N,
18.17. Found: C, 59.55; H, 5.99; N, 18.06.
1756 (lactone CO), 1742 (OAc), 1704, 1654, 1542 (C@C and NHAc)
cmꢀ1. Anal. Calcd for C9H11NO5: C, 50.71; H, 5.20; N, 6.57. Found: C,
50.97; H, 5.23; N, 6.59.
3.3.9. 2-Acetamido-3,4,5-tri-O-acetyl-2-deoxy-D
-arabinose N,N0-
diphenylformazan (10)
3.3.14. 2-Acetamido-5-O-acetyl-2,3-dideoxy-L-glycero-pent-2-
Acetylation of compound 8 (1.0 g, 2.6 mmol) with Ac2O (3 mL)
in dry pyridine (5 mL) and conventional work-up resulted in crude
9 as red solid (1.27 g, 96%), mp 79–81 °C. Recrystallization from
ethanol by adding a few drops of water afforded red needles
(1.0 g, 75%), mp 88–89 °C. Anal. Calcd for C25H29N5O7: C, 58.70;
H, 5.71; N, 13.69. Found: C, 58.83; H, 5.65; N, 13.48.
enono-1,4-lactone (15)
From compound 13, lactone 15 was prepared by the procedure
described for the synthesis of 14. White crystals of the pure prod-
uct were obtained in 45% yield, mp 155–157 °C; lit2 mp 160–
161 °C; [
a
]
ꢀ35 (c 2, EtOAc). IR and NMR data are identical with
D
those of compound 14. Anal. Calcd for C9H11NO5: C, 50.71; H,
5.20; N, 6.57. Found: C, 51.03; H, 5.21; N, 6.63.
3.3.10. 2-Acetamido-3,4,5-tri-O-acetyl-2-deoxy-
L-arabinose
N,N0-diphenylformazan (11)
3.3.15. 3,4,5-Tri-O-acetyl-D
-erythro-pent-2-enose N,N0-
diphenylformazan (17)
Starting from 9, by using the procedure described for the prep-
aration of 10, the corresponding L-enantiomer (11) was isolated in
Tetra-O-acetyl-D-ribose formazan (5, 4.017 g, 7.83 mmol) was
77% yield, mp 88–90 °C. 1H and 13C NMR data are identical with
those of compound 10. Anal. Calcd for C25H29N5O7: C, 58.70; H,
5.71; N, 13.69. Found: C, 58.91; H, 5.62; N, 13.46.
dissolved in dimethyl sulfoxide and the red solution was allowed
to stand at rt. After 5 days TLC (solvent C) indicated complete
conversion. The mixture was poured into ice-water (200 mL).
During standing at 0 °C for 3 days, the product solidified. It
was filtered and washed with cold water to give red powder
(3.28 g, 92%), mp 105–108 °C. Recrystallization from MeOH–
water (9:1, fifteen times volume) gave 17 (2.13 g, 60%) in the
form of red crystals, mp 118–120 °C; mmax 1758 (shoulder),
3.3.11. 2-Acetamido-2-deoxy-D-arabinono-1,4-lactone (12)
To a stirred suspension of crude 8 (10.0 g, 26 mmol) in etha-
nol (91 mL) was added dropwise CF3CO2H (20.4 mL, 265 mmol)
at 0 °C. Stirring was continued for 6 h at 0 °C, then the mixture
was allowed to stand at 0 °C overnight. Evaporation to dryness
resulted in dark syrup, which was triturated with EtOAc and
kept in refrigerator to give white crystals (2.95 g, 61.1%, mp
151–153 °C). The mother liquor was concentrated, dissolved in
a mixture of EtOAc (30 mL) and diethyl ether (50 mL) and was
extracted three times with water. The aqueous layer was stirred
with Amberlite IR-120(H+) ion-exchange resin for 30 min. After
filtration the filtrate was concentrated then co-distilled several
times with EtOAc to give a second crop of product (0.73 g, total
yield 75%). The crude product was dissolved in a mixture of
EtOAc–2-propanol (75 times volume), the solution was concen-
trated to half of its volume, then chilled to give the pure product
1746 (OAc), 1601, 1522, 1506 (C@C) cmꢀ1
23H24N4O6: C, 61.05; H, 5.35; N, 12.38. Found: C, 61.32; H,
. Anal. Calcd for
C
5.42; N, 12.50.
Acknowledgments
This work was supported by the Hungarian Scientific Research
Fund (OTKA K72973). The European Union and the European Social
Fund have provided financial support to the project under the
grant agreement No. TÁMOP 4.2.1./B-09/KMR-2010-0003. The help
of Gábor Pohl is appreciated.
Zsoldos-Mády, Virág
