280
A.M. Riley et al. / Carbohydrate Research 314 (1998) 277–281
1
3
and H-6), 4.81 (t, H-5); C NMR (CDCl3,
00 MHz) l 17.39 (Me), 17.54 (Me), 47.97
OMe), 48.19 (OMe), 66.17 (2×inositol C),
at reflux, a white precipitate of diol 5 began
1
to appear, and after 5 h TLC (EtOAc)
(
showed that no monoacetate (R 0.48) re-
f
6
8.05 (2×inositol C), 68.40 (inositol C-2),
4.71 (inositol C-5), 99.63 (2×BDA quater-
mained. Heating was discontinued and the
solution was stirred overnight. The white pre-
cipitate was filtered off, washed with MeOH
and dried to give the diol 5 as a white solid
(11.9 g, 29.1 mmol, 99%) which was used in
the next step without further purification. 5
Sublimes above 250 °C to give crystals with
8
nary C), 100.33 (2×BDA quaternary C),
18.60 (JCF 320 Hz, CF ); FABMS m/z 509.2
1
[
3
+
(M−MeO) , 100%], 101.1 (85%); FABMS
−
m/z 692.3 [(M+NBA−H) , 70%], 471.2
−
3
(
60%), 149.1 [CF SO , 100%]; Anal. Calcd
3
mp \300 °C (dec); R 0.24 (EtOAc); R 0.40
for C H F O S: C, 42.22; H 5.78. Found:
f
f
1
9
31
3
12
1
(
2:1 CHCl –acetone); H NMR (Me SO-d ,
C, 42.2; H, 5.82.
-O-acetyl-1,6:3,4-bis-O-(2,3-dimethoxybu-
tane-2,3-diyl)-neo-inositol (4).—A solution of
(16.6 g, 30.7 mmol) in dimethylacetamide
100 mL) and water (2 mL) was stirred at
0 °C for 3 h, after which time TLC (EtOAc)
showed total conversion of starting material
R 0.60) into a product (R 0.48). The sol-
3
2
6
2
70 MHz) l 1.18 (s, 12 H, Me), 3.13 (s, 12
2
H, OMe), 3.74 (br s, 4 H, H-1, H-3, H-4 and
H-6) 3.81 (br d, 2 H, J 4.6 Hz, H-2 and
3
H-5), 4.77 (d, 2 H, J 4.6 Hz, exch D O,
(
2
1
3
2
1
×OH); C NMR (Me SO-d , 67.8 MHz) l
5
2
6
7.87 (4×Me), 47.42 (4×OMe), 66.67 (C-1,
C-3, C-4, C-6), 67.59 (C-2 and C-5), 98.83
4×BDA quaternary C); FABMS m/z 431.1
(
f
f
(
vents were removed by evaporation in vacuo
at 50 °C to give an off-white solid. The solid
was taken up in CH Cl (200 mL), washed
with water (2×200 mL), dried (MgSO ) and
concentrated by evaporation under reduced
pressure to give 4 as a white solid (13.2 g,
9.3 mmol, 95%), which was used in the next
+
+
[
(M+Na) , 30%], 377.1 [(M−OMe) ,
1
00%], 101.0 (70%). An analytical sample was
2
2
obtained by sublimation: Anal. Calcd for
C H O : C, 52.93; H 7.90. Found: C, 52.7;
4
1
8
32 10
H, 7.96.
Neo-inositol (6).—A stirred suspension of
(11.3 g, 27.7 mmol) in 80% v/v aq AcOH
250 mL) was heated at reflux. The solid dis-
2
5
(
step without further purification. Crystals
from EtOH (needles) sublime above 200 °C
1
solved to give a clear solution and after a few
min a precipitate began to appear, accompa-
nied by a yellow coloration (butanedione).
After 4 h, heating was discontinued and sol-
vents were removed by evaporation in vacuo
at 50 °C. Co-evaporation with toluene
removed remaining traces of acetic acid giv-
ing a white solid (ꢀ5 g), which was recrys-
tallised from boiling water to give
neo-inositol (6) as colourless crystals (4.19 g,
to give new crystals with mp 262–265 °C; H
NMR (CDCl , 270 MHz) l 1.23 (s, 6 H,
3
Me), 1.31 (s, 6 H, Me), 2.12 (s, 3 H, Ac),
2
.44 (br s, 1 H, exch D O, OH), 3.24 (s, 6 H,
2
OCH ), 3.26 (s, 6 H, OCH ), 3.92 (dd, 2 H,
3
3
J4,3 and J6,1 10.3, J4,5 and J6,5 2.8 Hz, H-4
and H-6), 4.07–4.14 (m, 3 H, H-1, H-3 and
13
H-5), 5.46 (t, 1 H, J 2.9 Hz, H-2); C NMR
(
(
CDCl , 67.8 MHz) l 17.50 (2×Me), 17.63
3
2×Me), 21.11 [MeC(O)O], 47.94 (4×
2
3.3 mmol, 84%); mp\300 °C with sub-
OMe), 65.10 (2×inositol C), 67.12 (2×inos-
limation and decomposition, lit 315 °C
itol C), 68.83 (inositol C), 69.59 (inositol C),
1
(dec) [7]; H NMR (D O, 400 MHz) l 3.66
(br s, 4 H, H-1, H-3, H-4 and H-6), 3.95 (br
2
9
9.53 (2×BDA quaternary C), 99.79 (2×
BDA quaternary C), 170.46 (CꢀO); FABMS
s, 2 H, H-2 and H-5); Anal. Calcd for
C H O : C, 40.00; H 6.71. Found: C, 39.8;
+
m/z 473.2 [(M+Na) , 30%], 419.2
+
6
12
6
[
(M−MeO) , 100%], 101.1 (70%); Anal.
H, 6.72.
Calcd for C H O : C, 53.32; H 7.61.
2
0
34 11
Found: C, 53.3; H, 7.62.
,6:3,4 - bis - O - (2,3 - dimethoxybutane-2,3-
1
diyl)-neo-inositol (5).—To a stirred solution
of 4 (13.2 g, 29.3 mmol) in refluxing dry
Acknowledgements
MeOH (300 mL) under N was added a cata-
We thank the Wellcome Trust for Pro-
gramme Grant Support (045491).
2
lytic amount of NaOMe (100 mg). After 1 h