1,6-Anhydro-1-thio-β-D-glucopyranose (thiolevoglucosan) and the corresponding sulfoxides and sulfone

Article abstract of DOI:10.1135/cccc20060311

Starting 1,2,3,4-tetra-O-acetyl-6-O-tosyl-β-D-glucopyranose (3) was converted into 2,3,4-tri-O-acetyl-1-thio-6-O-tosyl-β-D-glucopyranose (6) via intermediate glycosyl bromide 4 and S-thiouronium salt 5. Treatment of compound 6 with sodium methoxide gave 1,6-anhydro-1-thio-β-D-glucopyranose (thiolevoglucosan 2a). The isomeric sulfoxides 7 and 8 were prepared by selective oxidation of thiolevoglucosan 2a with hydrogen peroxide or 3-chloroperoxybenzoic acid. The structure of new compounds was confirmed by ¹H and ¹³C NMR spectroscopy or by X-ray analysis; magnetic anisotropy of the sulfinyl and sulfonyl group has been discussed.

Full text of DOI:10.1135/cccc20060311

1,6-Anhydro-1-thio-β-D-glucopyranose
311
1,6-ANHYDRO-1-THIO-β-D-GLUCOPYRANOSE (THIOLEVOGLUCOSAN)
AND THE CORRESPONDING SULFOXIDES AND SULFONE
a,
c
Miloš BUDĚŠÍNSKÝ *, Jana POLÁKOVÁb1, Michaela HAMERNÍKOVÁ ,
d
b2
b3
Ivana CÍSAŘOVÁ , Tomáš TRNKA and Miloslav ČERNÝ
a
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic,
166 10 Prague 6, Czech Republic; e-mail: milos.budesinsky@uochb.cas.cz
Department of Organic Chemistry, Faculty of Science, Charles University,
128 40 Prague, Czech Republic; e-mail: polakova@natur.cuni.cz, trnka@natur.cuni.cz,
mila@natur.cuni.cz
Department of Biophysics and Physical Chemistry, Charles University,
500 05 Hradec Králové, Czech Republic; e-mail: hamernikova@faf.cuni.cz
Department of Inorganic Chemistry, Faculty of Science, Charles University,
128 40 Prague, Czech Republic; e-mail: cisarova@natur.cuni.cz
b
1
2
3
c
d
Received Septem ber 30, 2005
Accepted Decem ber 4, 2005
Dedicated to Professor Jaroslav Podlaha on the occasion of his 70th birthday.
Startin g 1,2,3,4-tetra-O-acetyl-6-O-tosyl-β-D-glucopyran ose (3) was con verted in to 2,3,4-tri-
O-acetyl-1-th io-6-O-tosyl-β-D-glucopyran ose (6) via in term ediate glycosyl brom ide 4 an d
S-th iouron ium salt 5. Treatm en t of com poun d 6 with sodium m eth oxide gave 1,6-an h ydro-
1-th io-β-D-glucopyran ose (th iolevoglucosan 2a). Th e isom eric sulfoxides 7 an d 8 were pre-
pared by selective oxidation of th iolevoglucosan 2a with h ydrogen peroxide or 3-ch loro-
peroxyben zoic acid. Th e structure of n ew com poun ds was con firm ed by 1H an d 13C NMR
spectroscopy or by X-ray an alysis; m agn etic an isotropy of th e sulfin yl an d sulfon yl group
h as been discussed.
Keyw ord s: Th io sugars; An h ydro sugars; Carboh ydrates; Sulfoxides; Sulfon es; Con form ation
an alysis; Pum m erer rearran gem en t; NMR spectroscopy; Magn etic an isotropy of sulfin yl
group; X-ray diffraction .
Ch em istry of 1,6-an h ydro-β-D-glucopyran ose (1a) h as been studied in detail
an d its usefuln ess for syn th esis of n um erous n atural products was dem on -
strated m an y tim es1. Less atten tion h as been paid to 1,6-an h ydro-1-th io-
β-D-glucopyran ose (th iolevoglucosan 2a) wh ich also m ay be of use in syn -
th esis. Both m en tion ed com poun ds, th iolevoglucosan 2 2a an d levogluco-
san 3 1a exh ibit structural sim ilarity as sh own by X-ray an alysis, but th ey
differ con siderably in reactivity m ain ly due to h igh n ucleoph ilicity of th e
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336
© 2006 Institute of Organic Chemistry and Biochemistry
doi:10.1135/cccc20060311

312
Buděšínský et al.:
sulfur bridge in 2a an d its n eigh borin g-group participation capabilities4–12
.
Previous syn th eses of th iolevoglucosan 2a in volve base catalyzed cyc-
lization of precursors con tain in g n ucleoph ilic sulfur group eith er at car-
bon C-1 or C-6 an d a leavin g group such as tosyloxy, m esyloxy, iodin e or
brom in e. Akagi10 an d Skelton 12 used 1,2,3,4-tetra-O-acetyl-1-th io-6-O-tosyl-
β-D-glucopyran ose or th e correspon din g 1-xan th ogen ate, Lun dt11 used
acetylated 6-brom o-6-deoxy-β-D-glucopyran osyl xan th ate. Driguez5 treated
2,3,4-tri-O-acetyl-6-O-tosyl-α-D-glucopyran osyl brom ide with h ydrogen sul-
fide or trieth ylam m on ium tetrath iom olybdate to obtain 2a in h igh yield.
An altern ative route13 leadin g to substituted 2a started from eth yl 1-th io-
4,6-di-O-tosyl-β-D-glucopyran oside an d in volved th e form ation of eth yl sul-
fon ium salt as in term ediate. On th e oth er h an d, Wh istler14 prepared 2a by
cyclization of 6-th io-β-D-glucopyran osyl brom ide.
In con n ection with th e recen t syn th esis12 of th iolevoglucosan an d related
an h ydro derivatives, we report h erein our results regardin g th e preparation
of th iolevoglucosan an d its reactivity in oxidation reaction s leadin g to th e
correspon din g sulfoxides an d sulfon e (see also refs12,15). Th eir structure,
con form ation al beh avior in solven ts of differen t polarity, as well as m ag-
n etic an isotropy of sulfin yl an d sulfon yl group is discussed.
RESULTS AND DISCUSSION
1,2,3,4-Tetra-O-acetyl-6-O-tosyl-β-D-glucopyran ose (3) was prepared accord-
in g to Hardegger’s procedure16a an d it was con verted in to th e glucosyl
brom ide 4 by treatm en t with h ydrogen brom ide in acetic acid16b. S-Th io-
uron ium salt 5 was prepared by alkylation of th iourea with brom ide 4 in
boilin g aceton e an d th en subjected to reductive cleavage in a two-ph ase
system (water–ch loroform ) to obtain th ioglucose 6. Th e crude reaction m ix-
ture con tain ed, in addition to m ajor th ioglucose 6, a m in or product of
in tram olecular n ucleoph ilic cyclization , tri-O-acetylth iolevoglucosan 2b.
Both com poun ds 2b an d 6 were con verted in to th e th iolevoglucosan 2a by
treatm en t with sodium m eth oxide in m eth an ol.
Sulfoxides 7a an d 8a were obtain ed by direct oxidation of un substituted
th iolevoglucosan 2a, in con trast to th e m eth od of Skelton 12 based on oxi-
dation of th iolevoglucosan triacetate 2b, followed by Zem plén deacetyl-
ation . In our h an ds, stereoselectivity of th e oxidation of th iolevoglucosan
2a h as been ch an ged by m odifyin g th e reaction con dition s. Th us, usin g h y-
drogen peroxide in acetic acid yielded m ore th an 65% of exo-sulfoxide 7a,
wh ile 3-ch loroperoxyben zoic acid in m eth an ol gave sign ifican t am oun ts of
both expected sulfoxides, n am ely 7a an d 8a. Surprisin gly, oxidation of 2a
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
313
with tert-butylh ydroperoxide in th e presen ce of (S)-BINOL afforded
endo-sulfoxide 8a as a sin gle product in alm ost quan titative yield. Th e X-ray
an alysis of 8a h as con firm ed th e endo-orien tation of oxygen of th e sulfin yl
group, th e structure of 7a h as been estim ated earlier17. A stereoselective oxi-
dation of cyclic sulfides with h ydrogen peroxide h as been already observed
an d several tim es discussed in th e literature (see, e.g., ref.18a,b, cf. review18c).
Treatm en t of th iolevoglucosan 2a or its acetate 2b with an excess of oxidiz-
in g agen t resulted in th e form ation of sulfon es 9a an d 9b, respectively. For
1
solid state, th e X-ray an alysis of 7a, 8a, an d 9a eviden ced th e C4 con for-
m ation for each of th ese com poun ds. However, th eir con form ation in solu-
tion m ay ch an ge in depen den ce on th e solven t polarity (see below).
Sulfoxide 7a, wh en h eated with sodium acetate in acetic acid un derwen t
th e Pum m erer rearran gem en t to give a m ixture con tain in g m ajor com -
poun d 10, as in dicated by NMR spectra. Its deacetylation led to an un stable
product, wh ich decom posed on stan din g.
Attem pted tosylation of th iolevoglucosan 2a in pyridin e, th e reaction fre-
quen tly used for th e tran sform ation of levoglucosan , failed, probably due
to th e participation of sulfur atom 12,15b an d form ation of an un stable sul-
fon ium salt an d its subsequen t decom position . On th e oth er h an d, partial
ben zoylation of th iolevoglucosan 2a yielded a m ixture of diben zoyl an d
triben zoyl derivatives 11 an d 12, respectively. Mesylation of 12 led to a sta-
ble m esylate 13 (Sch em e 1).
NMR Spectra
Th e structures of all syn th esized com poun ds 1–13 were con firm ed by 1H
an d 13C NMR spectra (data are sum m arized in Tables I–III). Structural as-
1
sign m en t of proton sign als was obtain ed usin g H,1H-COSY spectra, ch arac-
teristic splittin g pattern an d ch em ical sh ifts. Couplin g con stan ts were
derived from expan ded resolution en h an ced spectra. Hom on uclear decoup-
lin g experim en ts were used to determ in e th e values of som e sm all couplin g
con stan ts. Carbon sign als were assign ed from APT an d 2D-HMQC spectra.
Replacem en t of th e oxygen atom in 1,6-an h ydride bon d (levoglucosan
1a) with sulfur atom (th iolevoglucosan 2a) leads to prolon gation of C(1)–X
an d C(6)–X bon ds wh ich could in duce som e ch an ges in th e con form ation
of th e bicyclic system . Th e com parison of X-ray data of th iolevoglucosan
an d levoglucosan as well as th e calculation of its en ergy m in im ized con for-
m ation s sh ow th at th ese ch an ges are rath er sm all (see Table IV).
Replacem en t of oxygen atom with sulfur m an ifests itself in th e NMR
spectra by sign ifican t upfield sh ifts of H-6en (~1.0 ppm ), H-6ex (~0.6 ppm ),
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

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Buděšínský et al.:
SCHEME 1
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
315
TABLE I
Proton NMR ch em ical sh ifts in com poun ds 1–13
Com pd Solv.
H-1
H-2
H-3
H-4
H-5
H-6en H-6ex Oth er proton s
1a
CDCl3
5.51
3.62
3.80
3.75
4.58
4.22
3.80
OH(2): 2.39; OH(3): 2.41;
OH(4): 2.41
D2O
5.46
5.47
5.55
3.53
4.61
3.75
3.69
4.86
3.77
3.68
4.65
3.72
4.63
4.63
4.88
4.10
4.10
3.22
3.76
3.81
3.21
–
1b
2a
CDCl3
CDCl3
3×OAc: 2.16, 2.13, 2.10
OH(2): 2.76; OH(3): 3.70;
OH(4): 2.44
CD3OD
D2O
5.31
5.47
5.46
5.65
3.51
3.68
4.73
5.04
3.52
3.62
4.98
5.20
3.42
3.60
4.64
5.04
4.66
4.82
4.79
3.84
3.07
3.13
3.19
4.16
2.99
3.10
3.08
4.10
–
–
2b
3
CDCl3
CDCl3
3×OAc: 2.15, 2.14, 2.10
4×OAc: 2.09, 2.01, 2.00,
1.99; Tos: 7.77(2H),
7.34(2H), 2.45(3H)
4
CDCl3
CDCl3
6.46
4.47
5.20
4.72
4.87
3.84
5.49
5.15
3.76
5.09
4.96
3.44
4.28
3.74
5.11
~4.16 ~4.16 3×OAc: 2.08, 2.02, 2.00;
Tos: 7.79(2H), 7.36(2H),
2.46(3H)
6
4.14
4.06
3×OAc: 2.06, 2.00, 1.99;
SH:2.22; Tos: 7.79(2H),
7.36(2H), 2.46(3H)
a
7a
CDCl3
4.12
2.65
OH(2): 4.73; OH(3): 5.07;
OH(4): 4.65
CD3OD
D2O
5.18
5.37
5.38
5.57
3.79
3.96
4.49
4.30
3.67
3.78
4.81
3.94
3.41
3.58
4.86
3.91
5.10
5.22
5.26
4.65
4.13
4.18
3.93
3.27
2.65
2.81
2.91
3.59
–
–
7b
8a
CDCl3
CDCl3
3×OAc: 2.19, 2.18, 2.14
OH(2): 2.93; OH(3): 6.00;
OH(4): 2.52
(CD3)2CO 5.58
4.14
3.72
3.69
4.61
3.00
3.63
OH(2): 4.49; OH(3): 5.66;
OH(4): 4.34
CD3OD
D2O
5.50
5.67
5.54
4.71
4.18
4.22
5.63
4.09
3.65
3.71
5.47
3.94
3.58
3.68
4.81
3.67
4.56
4.72
4.64
4.87
2.83
2.93
3.23
3.60
3.44
3.50
3.11
3.32
–
–
8b
9a
CDCl3
3×OAc: 2.13, 2.12, 2.09
a
CDCl3
OH(2): 4.84; OH(3): 4.34;
OH(4): 4.52
CD3OD
D2O
4.65
4.97
4.82
5.56
4.03
4.12
5.30
4.73
3.73
3.84
5.11
5.15
3.58
3.74
4.74
4.64
4.82
4.98
4.93
4.72
3.42
3.33
–
–
~3.55 ~3.55
9b
10
CDCl3
CDCl3
~3.46 ~3.46 3×OAc: 2.17, 2.16, 2.14
6.27
3.44
3.43
3.50
–
4×OAc: 2.14, 2.13, 2.10,
2.08
11
12
13
CDCl3
CDCl3
CDCl3
5.77
5.77
5.63
5.02
5.16
5.16
4.07
5.58
5.19
5.06
5.06
5.05
5.05
5.07
4.97
3.25
3.32
3.18
2×OBz: 8.09(4H), 7.59(2H),
7.40(4H); OH: 3.62
3×OBz: 8.11(6H), 7.60(3H),
7.48(6H)
2×Bz: 8.12(4H), 7.46(4H),
7.62(2H); SO2CH3: 3.06
a
DMSO-d6 (5 drops) was added to dissolve th e sam ple in CDCl3 (0.6 m l).
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

316
Buděšínský et al.:
TABLE II
1H-1H NMR couplin g con stan ts of com poun ds 1–13
Com pd Solv.
1,2
2,3
3,4
4,5
5,6en 5,6ex 6en ,6ex 1,3
2,4
3,5
a
1a
CDCl3
D2O
2.1
1.7
1.7
2.1
1.2
1.1
7.9
4.0
9.7
2.3
2.3
0.6
1.6
1.7
2.3
1.8
1.8
3.3
3.3
9.2
9.9
9.3
2.4
~2.0
2.0
1.8
2.9
5.9
6.6
7.2
2.9
3.6
3.8
4.3
3.3
2.8
4.9
1.9
2.5
2.0
1.9
4.7
4.7
9.3
9.8
9.3
2.4
2.4
2.0
2.0
3.3
6.25
7.3
8.5
3.6
4.0
4.7
6.2
2.5
3.6
6.5
2.0
1.7
1.8
1.8
2.0
1.9
9.9
10.2
10.0
2.3
~2.0
0.8
2.2
2.1
2.0
1.9
2.2
2.3
2.2
2.2
0.9
1.2
5.4
5.8
7.7
7.7
1.9
1.5
1.3
1.9
1.1
1.1
1.7
1.4
0.8
1.8
1.0
0.6
1.9
1.5
1.5
1.8
1b
2a
CDCl3
CDCl3
D2O
1.1
5.7
7.8
b
c
c
c
1.6
1.1
3.3
~3.3
3.2
0.9
1.1
1.1
1.4
1.3
1.25
1.2
1.0
5.9
6.4
4.2
~3.3
5.0
8.3
8.3
8.6
8.6
8.4
7.8
7.6
7.0
10.3
10.0
2b
3
CDCl3
CDCl3
CDCl3
CDCl3
CDCl3
D2O
0.9
11.1
c
4
6
11.1
12.5
13.6
13.6
13.7
13.8
13.6
14.0
13.5
d
7a
1.6
1.6
1.5
1.7
1.1
0.5
1.5
0.7
1.8
1.6
1.2
0.4
0.7
1.6
1.6
1.8
1.8
1.4
0.6
7b
8a
CDCl3
CDCl3
(CD3)2COe 1.8
CD3ODf
1.4
1.3
1.0
1.7
<1
D2O
8b
9a
CDCl3
d
CDCl3
1.5
9.3
12.3
1.3
1.1
1.3
c
c
c
D2O
c
c
9b
10
11
12
13
CDCl3
CDCl3
1.2
0.9
1.6
1.3
0.8
12.8
–
2.1
0.4
0.8
0.9
0.7
–
0.8
1.6
1.3
0.7
0.6
1.3
g
c
CDCl3
6.8
6.8
6.0
10.2
10.1
10.0
0.85
0.8
CDCl3
CDCl3
1.8
2.1
0.5
0.4
a
b
Addition al J(H,H): J(OH,2) = 8.5, J(OH,3) = 7.5, J(OH,4) = 7.2; J(OH,2) = 8.0, J(OH,3) =
c
d
9.9, J(OH,4) = 6.8; J-value could n ot be determ in ed; DMSO-d6 (5 drops) was added to dis-
e
solve th e sam ple in CDCl3 (0.6 m l); J(1,4) = 0.6, J(1,6ex) = 0.6, J(OH,2) = 7.6, J(OH,3) = 7.4,
J(OH,4) = 6.3; J(1,4) ≤ 0.3, J(1,6ex) = 0.6; J(OH,3) = 8.1.
f
g
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
317
TABLE III
Carbon -13 NMR ch em ical sh ifts of com poun ds 1–13
Com pd Solv.
C-1
C-2
C-3
C-4
C-5
C-6
Oth er carbon s
–
1a
1b
D2Oa
104.28 73.03
75.35
69.71
73.65
70.44
79.11
73.79
68.04
65.38
CDCl3
99.28
69.23
3×OAC: 170.00, 169.61,
169.02, 20.93, 20.83(2)
2a
CDCl3
D2O
83.28
86.57
81.70
72.43b
77.76
74.16
72.02b
75.33
69.04
71.95b
74.87
72.07
80.96
84.42
79.52
33.12
36.75
34.40
–
–
2b
4
CDCl3
3×OAc: 170.15, 169.88,
169.34, 20.87(3)
CDCl3
86.06
71.58b
70.36b
70.01b
67.15b
66.25
3×OAc:169.85, 169.63,
169.14, 20.57(2), 20.43;
Tos: 145.22, 132.79,
129.87(2), 128.09(2), 21.66
7a
7b
D2Oa
104.93 70.03
100.01 67.97
71.74
67.12
71.07
64.97
84.10
78.65
61.32
58.99
–
CDCl3
3×OAc: 169.63, 169.22,
167.61, 20.81, 20.72, 20.68
8a
8b
D2Oa
97.26
92.91
66.70
65.20
75.15
68.32
75.76
73.42
85.63
81.57
56.51
55.55
–
CDCl3
3×OAc: 170.66, 170.00,
169.96, 20.85, 20.80, 20.65
9a
9b
D2Oa
91.76
86.69
70.56
67.34
74.18
68.00
72.95
70.49
81.36
76.70
52.45
50.49
–
CDCl3
3×OAc: 170.10, 169.25,
169.08, 20.82, 20.70, 20.67
10
11
CDCl3
CDCl3
83.10
81.40
74.54
73.94
69.47
69.25
69.97
74.78
84.73
79.35
82.49
34.31
4×OAc: 170.25, 170.04,
169.99, 169.42, 20.88,
20.86, 20.85, 20.74
2×Bz: 165.73, 165.71,
133.52(2), 133.47(2),
129.95(2), 129.90(2),
129.49, 129.35, 128.43(4)
12
13
CDCl3
81.72
82.40
73.52
76.95
68.95
75.75
71.71
73.40
78.97
80.90
33.99
35.60
3×Bz: 165.56, 165.37,
164.96, 133.58(2), 133.51,
130.00(4), 129.96(2),
129.30, 129.23, 129.11,
128.57(2), 128.46(2),
128.43(2)
CDCl3
SO2CH3: 39.00; 2×Bz:
165.83, 165.60, 133.83(2),
130.04(2), 130.00(2),
128.79, 128.75, 128.63(2),
128.61(2)
a
b
Spectrum could n ot be obtain ed in CDCl3 due to very poor solubility; th e assign m en t of
sign als m ay be in terch an ged.
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318
Buděšínský et al.:
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1,6-Anhydro-1-thio-β-D-glucopyranose
319
C-6 (~30 ppm ) an d C-1 (~18 ppm ). Th e determ in ation of th e con figuration
of S–O group in isom eric sulfoxides from NMR spectra is n ot easy task due
to th e absen ce of an y related couplin g con stan t. Th e use of som e NMR
ch iral sh ift reagen ts 1-(9-an th ryl)-2,2,2-trifluoroeth an ol, m eth oxy(ph en yl)-
acetic acid (MPA), m eth oxy(1-n aph th yl)acetic acid (1-NMA) or m eth oxy-
(2-n aph th yl)acetic acid (2-NMA), N-(2,4-din itroben zoyl)-1-ph en yleth yl-
am in e was suggested in th e literature20–25 for stereoch em ical an alysis of
sulfoxides. We h ave applied th e MPA as ch iral sh ift reagen t to sulfoxide
triacetates 7b, 8b but th e in duced 1H an d 13C ch em ical sh ifts could n ot be
in terpreted un equivocally in th e sen se of th e con figuration of th ese
sulfoxides. Th e recen t m eth od for th e determ in ation of th e absolute con fig-
uration of ch iral sulfoxides described by Yabuuch i an d Kusum i26 seem s to
be m ore effective but it was n ot applied.
Magn etic an isotropy of th e S–O group h as been discussed in literature.
Th e early in vestigation s in dicated th at th e proton s in cis-arran gem en t with
S–O group were desh ielded wh ile in trans-arran gem en t sh ielded27,28. Later
studies29–33 revealed th e in fluen ce of th e lon e pair on th e sh ieldin g or
desh ieldin g of n eigh borin g proton s. Every group in anti position to th e
lon e pair sh ould be sh ielded, wh ich is in discrepan cy with previous obser-
vation s.
Sin ce in our case th e con figuration of sulfoxides was un equivocally deter-
m in ed by X-ray m easurem en t, we could an alyse th e effects observed in th eir
NMR spectra in detail. Ch an ges in proton an d carbon -13 ch em ical sh ifts in -
duced by oxidation of sulfide to exo-sulfoxide, endo-sulfoxide an d sulfon e
are sum m arized in Tables V an d VI. Th e exo-sulfoxides 7a, 7b sh ow very
pron oun ced ch em ical sh ift differen ce between H-6en an d H-6ex (∆δ = 1.02
to 1.47 ppm ) sin ce th e in troduction of S–O group in duces an upfield sh ift
of H-6ex syn-orien ted to S–O (–0.17 to –0.56 ppm ) an d th e opposite down -
field sh ift for H-6en syn-orien ted to sulfur lon e pair (0.74 to 1.05 ppm ). On
th e oth er h an d, in endo-sulfoxides 8a, 8b th ere are H-6en an d H-6ex m uch
closer (∆δ = 0.12 to 0.63 ppm ) as th e result of sm all in duced sh ift to both
H-6en syn-orien ted to S–O (–0.20 to 0.05 ppm ) an d H-6ex syn-orien ted to
sulfur lon e pair (0.03 to 0.40 ppm ). Th e 13C NMR spectra sh owed m ost
ch aracteristic differen ces for C-1 with n early twice larger down field sh ift for
exo-sulfoxides 7a, 7b (~18 ppm ) th an for endo-sulfoxides 8a, 8b (~11 ppm ).
Alth ough th e X-ray as well as calculated data sh ow very sim ilar absolute
values of torsion an gles between oxygen atom an d H-6 proton s with syn-
an d anti-orien tation in both sulfoxides (see Table VII), th e in duced sh ifts
are sign ifican tly differen t. Th is can be caused by a differen t ch em ical en vi-
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320
Buděšínský et al.:
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1,6-Anhydro-1-thio-β-D-glucopyranose
321
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

322
Buděšínský et al.:
ron m en t of th e endo- an d exo-orien ted sulfoxide group in 7a an d 8a, to-
geth er with certain differen ces in th e con form ation of pyran ose rin g.
Th e con form ation of pyran ose rin g can be m on itored by vicin al proton
couplin gs J(2,3) an d J(3,4) wh ich are kn own to be very sen sitive to th e pop-
ulation of th e ch air an d boat form in solution 34,35. Table VIII sh ows th e cal-
culated ch air-boat population s in levoglucosan 1a, th iolevo-glucosan 2a,
sulfoxides 7a, 8a, sulfon e 9a an d th eir acetates 1b, 2b, 7b, 8b an d 9b. It can
be seen th at population of th e ch air con form ation 1C4 depen ds to a sm aller
or larger exten t n ot on ly on th e structure but also on th e type of solven t.
Th e con ten t of th e boat con form ation B3,O is h igh er for acetates th an for
h ydroxy com poun ds an d it in creases also wh en goin g from CDCl3 to water
as th e solven t. For endo-sulfoxide 8a we could observe a dram atic decrease
in th e ch air form con ten t in th e series of solven t with in creasin g perm it-
tivity – CDCl3 (94%), CD3COCD3 (74%), CD3OD (25%), D2O (11%). It
seem s th at in com poun ds with endo-S–O group th e ch air form can be stabi-
lized by h ydrogen bon d between C(3)–OH an d S–O, th e existen ce of wh ich
is less favored in polar solven ts an d it is excluded in acetates (~100% boat
form calculated for endo-sulfoxide triacetate 8b).
To ch eck wh eth er th e above discussed differen t in duced sh ifts of H-6en
an d H-ex are usable for determ in ation of th e con figuration of sulfoxide
group in oth er 1,6-an h ydro-1-th io-β-D-h exopyran ose derivatives we h ave
m easured an d an alyzed NMR data of a recen tly prepared series of com -
poun ds 15–18 (Sch em e 2) derived from 1,6-an h ydro-1-th io-β-D-galactose36
(syn th esis of th ese com poun ds will be described in a separate paper). Th e
NMR data of th ese com poun ds togeth er with data of 1,6-an h ydro-
β-D-galactopyran ose (14) for com parison are sh own in Tables IX–XI.
TABLE VII
Th e X-ray determ in ed an d calculated torsion an gles between oxygen atom s of sulfoxides 7a,
8a an d h ydrogen atom s H-6en an d H-6ex
exo-Sulfoxide 7a
endo-Sulfoxide 8a
Torsion an gle
X-ray
calc.
X-ray
calc.
H6en –C6–S–Oen
H6ex–C6–S–Oen
H6en –C6–S–Oex
H6ex–C6–S–Oex
–
–
–
11.8
5.9
–
128.9
124.0
–136.0
–15.4
–131.3
–13.0
–
–
–
–
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
323
TABLE VIII
Ch air–boat equilibrium calculated from 1H-1H NMR couplin g con stan ts J(2,3) an d J(3,4) in
com poun ds:
Com pd.
X
O
R
H
Solven t
Ch air, %a
1a
CDCl3
D2O
95
86
94
95
60
60
85
88
92
94
74
25
11
0
1b
2a
O
S
Ac
H
CDCl3
CDCl3
D2O
2b
7a
S
Ac
H
CDCl3
b
SO (exo)
CDCl3
D2O
7b
8a
SO (exo)
Ac
H
CDCl3
CDCl3
CD3COCD3
CD3OD
D2O
SO (endo)
8b
9a
SO (endo)
Ac
H
CDCl3
b
SO2
CDCl3
72
63
55
D2O
9b
SO2
Ac
CDCl3
a
Th e average values of th e ch air population calculated from J(2,3) an d J(3,4) are given ;
DMSO-d6 (5 drops) was added to dissolve th e sam ple in CDCl3 (0.6 m l).
b
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

324
Buděšínský et al.:
Th e values of couplin g con stan t J(2,3) for com poun ds 15–18 sh ow a very
sm all population of th e boat form of h exapyran ose rin g in th e wh ole series.
Ch an ges in proton an d carbon -13 ch em ical sh ifts in duced by oxidation of
sulfides 15a, 15b to sulfoxides 16a, 16b, 17a, 17b an d sulfon es 18a, 18b
are sum m arized in Tables V an d VI. On e of th e sulfoxides sh ows again a
large n on -equivalen ce of th e ch em ical sh ifts of H-6en an d H-6ex wh ich in -
dicates, in an alogy to th e above discussed gluco derivatives, th e exo-con figu-
ration of th e S–O group (sulfoxide 16a). Th e secon d sulfoxide h as m uch
closer H-6en an d H-6ex sign als an d could be assign ed (per an alogy) to
endo-sulfoxide 16b. Perh aps th e m ost straigh tforward an d easy in terpretable
NMR param eter for distin guish in g th e exo- an d endo-sulfoxide in both gluco
an d galacto derivatives is th e ch em ical sh ift of H-2. Proton H-2 sh ows dra-
m atic down field sh ift (0.55–0.70 ppm ) in case of endo-sulfoxide, obviously
due to th e van der Waals desh ieldin g effect of th e S–O group wh ich is in
SCHEME 2
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
325
1,3-syn-axial relation to H-2 (distan ce H(2)···O
2.75 Å). Th e down field
sh ift is still pron oun ced (0.90 ppm ) in endo-sulfoxide triacetate 8b with
~100% of th e boat form , wh ich brin gs H-2 still m ore close to th e S–O oxy-
gen (distan ce H(2)···O 2.45 Å). Th e proton ch em ical sh ifts in duced by th e
oxidation of sulfides to sulfoxides an d sulfon es are graph ically sh own in
Figs 1 an d 2.
X-ray Structure Analysis of 8a and 9a
A perspective view of th e endo-sulfoxide 8a with atom n um berin g is de-
picted in Fig. 3. Th e distan ces an d an gles of n on -h ydrogen atom s in both
rin gs of endo-sulfoxide are un exception ally close to th ose in exo-sulfoxide
7a (ref.17). Also th e con form ation s of th e rin gs rem ain th e distorted ch air as
follow from th e rin g puckerin g param eters38 for th e pyran ose rin g (θ =
159.7(2)°, ϕ = 173.4(6)°; O5 as pivot atom ) an d en velope (ϕ = 247.0(2)°, S1
as pivot atom ) for th e 1,3-oxath iolan e rin g.
TABLE IX
Proton NMR ch em ical sh ifts in galacto derivatives 14–18
Com pd Solv.
H-1
H-2
H-3
H-4
H-5
H-6en H-6ex Oth er proton s
14a
CDCl3
5.44
3.87
3.95
4.01
4.47
4.22
3.69
2-OH: 2.00; 3-OH: 2.51;
4-OH: 2.99
D2O
5.40
5.41
5.46
3.79
4.74
4.00
3.93
5.23
3.87
4.04
5.23
3.95
4.49
4.47
4.84
4.31
4.33
3.33
3.65
3.72
3.03
–
14b
15a
CDCl3
CDCl3
3×OAc: 2.13(2), 2.02
2-OH: 2.30; 3-OH: 3.68;
4-OH: 3.16
D2O
5.44
5.48
5.17
3.94
4.86
4.05
3.87
5.15
3.82
3.97
5.20
3.97
4.77
4.79
4.98
3.36
3.38
4.28
3.00
3.08
2.47
–
15b
16a
CDCl3
CDCl3
3×OAc: 2.14, 2.13, 2.07
a
2-OH: 5.07; 3-OH: 4.40;
4-OH: 4.37
D2O
5.31
5.38
5.55
4.15
5.04
4.55
3.89
5.14
3.99
4.00
5.20
4.20
5.10
5.17
4.59
4.39
4.17
3.23
2.60
2.78
3.40
–
16b
17a
CDCl3
CDCl3
3×OAc: 2.18, 2.15, 2.05
2-OH: 2.38; 3-OH: 6.24;
4-OH: 3.53
D2O
5.66
5.36
4.91
4.80
4.42
5.56
4.29
5.30
3.96
5.23
4.12
5.26
4.26
5.46
4.21
5.39
4.66
4.64
4.94
4.97
3.32
3.31
3.80
3.65
3.61
3.41
3.39
3.37
–
17b
18a
18b
CDCl3
D2O
3×OAc: 2.17, 2.13, 2.12
–
CDCl3
3×OAc: 2.18(2), 2.10
a
DMSO-d6 (5 drops) was added to dissolve th e sam ple in CDCl3 (0.6 m l).
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

326
Buděšínský et al.:
FIG. 1
1H NMR ch em ical sh ift ch an ges of H-6en an d H-6ex in duced by oxidation of th iols 2a, 15a to
exo-sulfoxides 7a, 16a, endo-sulfoxides 8a, 17a an d sulfon es 9a, 18a in D2O
FIG. 2
1H NMR ch em ical sh ift ch an ges of H-6en an d H-6ex in duced by oxidation of th iols 2b, 15b to
exo-sulfoxides 7b, 16b, endo-sulfoxides 8b, 17b an d sulfon es 9b, 18b in CDCl3
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
327
Major ch an ges appear in th e h ydrogen -bon d n etwork (Table XII). Con -
trary to exo-sulfoxide 7a wh ere th e sulfoxide oxygen was in volved in a
sh ort in term olecular h ydrogen bon d (average O3–O1 2.673 Å), in th e
endo-sulfoxide 8a th e orien tation of sulfoxide oxygen en ables th e form a-
tion of in tram olecular h ydrogen bon d O3···O1, wh ich by its len gth s
2.622(2) Å is th e ten th sh ortest from 89 in tram olecular con tacts between
th e (C)2–S–O m oiety an d h ydroxyl group foun d in th e Cam bridge Struc-
tural Database. At th e sam e tim e O3 is acceptor of h ydrogen from
in term olecular bon d with O4, wh ich togeth er with O2···O5 in teraction is
buildin g th e th ree dim en sion al n et in th e crystal.
TABLE X
1H-1H NMR couplin g con stan ts in galacto derivatives 14–18
Com pd Solv.
1,2
2,3
3,4
4,5
5,6en 5,6ex 6en ,6ex 1,3
2,4
3,5
4,6ex
a
c
14a
CDCl3
D2Ob
2.1
2.0
1.4
1.9
1.8
1.7
2.0
2.0
1.7
1.6
1.6
1.3
1.5
1.4
1.8
1.6
1.4
2.0
1.8
1.8
2.5
2.7
2.35
1.7
2.55
2.9
2.2
2.0
5.1
5.1
5.3
5.25
5.1
5.3
4.1
3.8
4.3
5.1
5.0
5.0
4.6
4.9
4.5
4.1
4.4
5.2
4.8
4.6
4.6
4.6
4.6
5.1
5.0
5.0
4.6
4.6
0.65
0.8
0.7
0.7
0.9
0.9
0.7
0.8
0.8
1.05
1.2
1.5
1.4
1.4
4.8
5.2
5.3
6.8
7.3
7.2
7.6
7.6
7.45
7.95
8.0
7.8
9.0
8.9
8.0
1.6
1.4
1.3
1.8
1.5
1.4
1.5
1.4
1.6
1.3
1.1
1.0
1.4
1.4
–
1.3
1.4
1.3
1.1
1.2
1.2
1.2
1.1
1.3
1.1
1.0
1.0
1.4
1.3
1.15
1.2
0.8
0.8
0.9
0.8
0.8
0.9
1.1
1.05
0.9
0.7
–
7.6
0.6
–
14b
15a
CDCl3
CDCl3
D2Od
7.7
10.65
10.4
10.0
12.8
13.3
13.2
14.1
14.0
13.2
13.0
12.8
0.5
0.5
0.6
≤0.5
0.6
0.5
0.9
0.5
0.45
–
e
f
15b
16a
CDCl3
CDCl3
D2Og
h
i
16b
17a
CDCl3
CDCl3
D2Oj
k
17b
18a
18b
CDCl3
D2Ol
m
CDCl3
0.6
0.6
a
Addition al J(H,H): J(1,6ex) = 0.5, J(1,6en ) = 0.35, J(OH,2) = 9.9, J(OH,3) = 8.1, J(OH,4) =
b
c
8.7; J(1,5) < 0.3, J(1,6en ) < 0.3, J(1,6ex) = 0.5, J(2,5) = 0.6; J(OH,2) = 8.8, J(OH,3) = 10.7,
d
e
J(OH,4) = 8.7, J(1,6ex) ≤ 0.5, J(2,5) = 0.55;
J(1,6ex) = 1.3, J(OH,2) = 5.8, J(OH,3) = 2.3, J(OH,4) = 7.0; J(1,6ex) = 1.25, J(2,5) = 0.6,
J(1,5) = 0.6, J(1,6en ) = 0.7;
J(2,5) = 0.6; J(2,5) = 0.5, J(1,6ex) ≤ 0.3;
f
g
h
J(1,6en ) = 0.7, J(1,6ex) = 1.25, J(1,5) < 0.5, J(2,5) = 0.5;
i
j
k
J(OH,2) = 8.2, J(OH,3) = 8.8, J(OH,4) = 8.8, J(1,6en ) = 0.65; J(1,6en ) = 0.65; J(1,6en ) =
l
m
0.5; J(1,6ex) = 1.5; J(1,6ex) = 1.3, J(1,5) ≤ 0.5, J(2,5) = 0.4.
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

328
Buděšínský et al.:
FIG. 3
Molecular structure of 8a, displacem en t ellipsoids are drawn 37 on 50% probability level.
Selected bon d distan ces (in Å) an d an gles (in °): S(1)–O(1) 1.5182(14), S(1)–C(1) 1.8601(19),
S(1)–C(6) 1.8295(18); O(1)–S(1)–C(6) 107.23(8), O(1)–S(1)–C(1) 108.85(9), C(6)–S(1)–C(1)
89.42(9)
FIG. 4
Molecular structure of 9a, displacem en t ellipsoids are drawn 37 on 50% probability level. Se-
lected bon d distan ces (in Å) an d an gles (in °): S(1)–O(11) 1.4367(11), S(1)–O(12) 1.4468(11),
S(1)–C(1) 1.8190(15), S(1)–C(6) 1.7858(15); O(11)–S(1)-O(12) 116.57(7), O(11)–S(1)–C(6)
114.77(8), O(12)–S(1)–C(6) 108.60(8), O(11)–S(1)–C(1) 112.86(7), O(12)–S(1)–C(1) 108.11(7),
C(6)–S(1)–C(1) 93.41(7)
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
329
TABLE XI
13C NMR ch em ical sh ifts in galacto derivatives 14–18
Com pd Solv.
C-1
C-2
C-3
C-4
C-5
C-6
Oth er carbon s
–
14a
14b
D2O
103.38 73.97
72.86
67.36
66.97
64.72
77.01
72.02
66.25
64.37
CDCl3
98.84
70.96
3×OAC: 169.42, 169.23,
169.07, 20.64, 20.57, 20.40
15a
CDCl3
D2O
82.39
85.02
80.99
73.40
76.82
73.59
70.96
73.03
67.37
64.44
67.75
65.62
79.86
81.11
76.04
29.88
31.94
30.75
–
–
15b
16a
CDCl3
3×OAc: 169.68, 169.42,
169.30, 20.91, 20.90, 20.65
CDCl3
D2O
102.76 68.37
104.40 70.97
100.13 66.91
70.08
72.15
66.97
63.54
66.13
64.16
79.59
82.37
77.34
57.84
59.66
58.13
–
–
16b
17a
CDCl3
3×OAc: 169.06, 168.92,
168.09, 20.68, 20.53, 20.50
CDCl3
D2O
91.70
93.73
87.68
69.06
70.63
66.78
68.35
72.01
67.53
64.37
67.57
65.48
76.97
79.57
74.55
48.58
50.46
48.52
–
–
17b
CDCl3
3×OAc: 169.86, 169.48,
168.98, 20.83(2), 20.67
18a
18b
D2O
90.01
84.70
71.06
67.14
72.54
67.08
65.98
63.96
78.38
73.15
49.77
47.81
–
CDCl3
3×OAc: 169.40, 169.16,
168.93, 20.86, 20.66, 20.51
TABLE XII
Param eters of h ydrogen bon ds in th e in vestigated crystals of com poun ds 8a an d 9a
Distan ces, Å
Specification
D–H···A
Bon d an gle, °
D H A
Com pd
D–H
H···A
D···A
8a
O2–H2···O5a
O4–H14···O3b
O3–H13···O1
O2–H12···O12c
O3–H13···O4d
O4–H14···O2e
0.77(3)
0.76(3)
0.83(3)
0.75(3)
0.85(3)
0.78(3)
2.20(3)
1.97(3)
1.81(3)
2.07(3)
2.14(2)
2.03(2)
2.842(2)
142(2)
172(3)
165(3)
172(2)
148(2)
172(2)
2.718(2)
2.622(2)
9a
2.8097(17)
2.8992(16)
2.8033(17)
a
b
Sym m etry tran sform ation s used to gen erate equivalen t atom s: 2 – x, y – 0.5, 1.5 – z; 0.5 +
c
d
e
x, –0.5 – y, 1 – z; 0.5 – x, –y, z – 0.5; 1 – x, 0.5 + y, 0.5 – z; 0.5 + x, –0.5 – y, 1 – z.
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330
Buděšínský et al.:
Th e view of m olecular structure of sulfon e 9a is represen ted in Fig. 4. Th e
m ajor ch an ge in th e con form ation of 9a can be observed in puckerin g of
5-m em bered rin g wh ich is close to h alf-ch air (ϕ = 237.3(2)°, S1 as pivot
atom ), wh ereas th e pyran ose rin g (θ = 155.7(1)°, ϕ = 165.0(4)°; O5 as pivot
atom ) preserves distorted ch air geom etry.
It is of in terest th at th e in crease in C–S–O an gles in th e sulfon e m oiety
brin gs its oxygen atom far from OH group an d would en able on ly a weak
in tram olecular h ydrogen bon d: th erefore, all h ydroxyls are in volved in
stron ger in term olecular h ydrogen bon d n etwork (Table XII).
EXPERIMENTAL
Meltin g poin ts were determ in ed usin g a Boëtius m icro m eltin g-poin t apparatus an d are un -
corrected. Th e optical rotation was m easured on a Ben dix–Ericsson ETL-143A polarim eter at
22 °C, [α]D values are given in 10–1 deg cm 2 g–1. NMR spectra (δ, ppm ; J, Hz) were m easured
on a Varian UNITY-500 in strum en t (1H at 500 MHz; 13C at 125.7 MHz) in CDCl3 an d/or D2O.
X-ray m easurem en t was perform ed on a Non ius KappaCCD diffractom eter (λ = 0.71069 Å,
150(2) K). Mass spectra were recorded on a Fin n igan MAT INCOS 50 spectrom eter usin g EI
ion ization (70 eV). Colum n ch rom atograph y was carried out on Kieselgel 60 (Merck,
0.063–0.200 m m ). Th in layer ch rom atograph y (TLC) was perform ed with Alufolien plates
(Merck 5554) an d com poun ds were visualized usin g a 50% sulfuric acid spray followed by
ch arrin g. Solution s were dried with an h ydrous m agn esium sulfate (un less oth erwise stated)
an d evaporated at a reduced pressure at tem peratures below 40 °C. An alytical sam ples were
dried over ph osph orous pen toxide at 0.1 Pa.
1,6-An h ydro-1-th io-β-D-glucopyran ose (2a)
Triacetate 2b (5 g, 16.4 m m ol) in absolute m eth an ol (10 m l) was treated with a 2 M solution
of sodium m eth oxide (2 m l). After 12 h at 0 °C, th e solution was n eutralized with acetic
acid an d evaporated to dryn ess. Th e residue was purified by colum n ch rom atograph y (150 g
silica gel, 5% m eth an ol in eth yl acetate) to give 2a (2.9 g, 99%) wh ich crystallized on stan d-
in g. Crystallization from eth an ol gave 2a, m .p. 165–180 °C (decom p.), [α]D –52 (c 0.75,
water), RF 0.47 (eth yl acetate–m eth an ol 9:1); ref.10 gives m .p. 180 °C (decom p.), [α]D –5.1
(c 0.8, water); th e latter [α]D value is obviously a typin g error; ref.14 gives [α]D –54 (c 1.0,
water).
2,3,4-Tri-O-acetyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (2b)
To a solution of sodium m eth oxide in m eth an ol (5 g of Na in 420 m l m eth an ol), th io-
glucose 6 (35 g, 0.073 m ol) was added an d th e reaction m ixture was kept at 4 °C for 12 h .
After n eutralization with acetic acid th e solven ts were evaporated an d th e residue (89 g)
con tain in g product 2a an d salts was refluxed in acetic an h ydride (150 m l) in th e presen ce of
an h ydrous sodium acetate (35 g) for 5 h . Th e reaction m ixture was th en poured in to ice
water an d extracted with ch loroform . Th e organ ic layer was wash ed with aqueous NaHCO3,
water, dried over an h ydrous CaCl2 an d evaporated to give 2b (12 g, 55%), m .p. 92–94 °C
(eth an ol), [α]D –50 (c 0.95, CHCl3); RF 0.74 (eth yl acetate–m eth an ol 9:1); ref.11 gives m .p.
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1,6-Anhydro-1-thio-β-D-glucopyranose
331
86–88 °C; ref.10 m .p. 93–94 °C, [α]D –25.2 (c 1.1, CHCl3); ref.14 m .p. 79–81 °C, [α]D –55
(c 0.3, CHCl3); ref.5 gives m .p. 79–81 °C, [α]D –51.6 (c 1.0, CHCl3).
1,2,3,4-Tetra-O-acetyl-6-O-tosyl-β-D-glucopyran ose (3)
To a cooled (<5 °C), stirred solution of an h ydrous D-glucose (200 g, 1.1 m ol) in dry pyridin e
(1 l), tosyl ch loride (220 g, 1.15 m ol) was added in portion s over a period of 30 m in . Th e re-
action m ixture was allowed to warm to room tem perature an d stirrin g con tin ued for 12 h .
Acetic an h ydride (800 m l, 7.8 m ol) was th en added to it dropwise durin g 2 h un der stirrin g
an d coolin g wh ile th e tem perature was m ain tain ed below 50 °C. Th e reaction m ixture was
allowed to stan d at room tem perature overn igh t. Th e precipitated product was filtered off
an d crystallized from ch loroform –eth an ol to give 3 (196 g, 35%); RF 0.34 (ben zen e–aceton e
10:1), m .p. 207–209 °C, [α]D +24 (c 0.8, CHCl3), in agreem en t with refs16a–16c. Moth er
liquors were worked up in usual way to give syrupy residue (320 g) wh ich con tain ed in addi-
tion to com poun d 3, th e correspon din g α-an om er an d 1,3,4-tri-O-acetyl-2,6-di-O-tosyl-
α-D-glucopyran ose16d,16e
.
2,3,4-Tri-O-acetyl-6-O-tosyl-α-D-glucopyran osyl Brom ide (4)
To a cooled solution (<10 °C) of h ydrogen brom ide in acetic acid (36%, 380 g) com poun d 3
(190 g, 0.38 m ol) was added in portion s. After 3 h , ch loroform (700 m l) was added an d th e
reaction m ixture was poured in to ice water. Th e organ ic layer was wash ed with water, n eu-
tralized with saturated solution of NaHCO3, purified with th e ch arcoal an d dried with an -
h ydrous CaCl2. Th e crude product was crystallized from th e m ixture dieth yl eth er–ligh t
petroleum to give brom ide 4 (142 g, 72%), RF 0.42, RF (3) 0.34 (ben zen e–aceton e 10:1), m .p.
110 °C, [α]D +166 (c 0.48, CHCl3); ref.16b gives m .p. 88–89 °C, [α]D +166.1 (c 3.75, CHCl3).
S-(2,3,4-Tri-O-acetyl-6-O-tosyl-β-D-glucopyran osyl)th iouron ium Brom ide (5)
Brom ide 4 (120 g, 0.23 m ol) was dissolved in dry aceton e (700 m l), th iourea (35 g, 0.46 m ol)
was added an d th e reaction m ixture was refluxed for 3 h (cf. ref.39). After coolin g, precipi-
tated crystals of crude th iouron ium salt 5 (95.5 g, 70%), were filtered off an d dried over
P2O5; after crystallization of 5 from aceton e–dieth yl eth er–ligh t petroleum , m .p. 169–170 °C,
[α]D +13 (c 0.28, water). Th e crude 5, con tain in g a sm all am oun t of th iol 6, was used with -
out furth er purification .
2,3,4-Tri-O-acetyl-1-th io-6-O-tosyl-β-D-glucopyran ose (6)
A m odified procedure40 was used for th e preparation of com poun d 6. To a suspen sion of th e
S-th iuron ium brom ide 5 (70 g, 0.12 m ol) in water (500 m l), ch loroform (250 m l) an d potas-
sium disulfite (70 g) were added. Th e reaction m ixture was refluxed for 2 h , th en allowed to
warm to room tem perature. Th e ch loroform layer was filtered, crystals of th e startin g m ate-
rial 5 (3.5 g) were separated, th e ch loroform solution was dried an d evaporated. Th e crude
th iol was purified by crystallization from dieth yl eth er–ligh t petroleum to give 6 (35 g,
65%), m .p. 168–170 °C, [α]D +29 (c 1.0, CHCl3), RF 0.3 (ben zen e–aceton e 10:1). For
C
19H24O10S2 (476.6) calculated: 47.90% C, 5.07% H, 13.46% S; foun d: 48.26% C, 5.34% H,
13.50% S. Moth er liquors con tain ed sm all am oun t of th iolevoglucosan triacetate 2b.
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332
Buděšínský et al.:
1,6-An h ydro-1-th io-β-D-glucopyran ose (S)-S-Oxide (7a) an d
1,6-An h ydro-1-th io-β-D-glucopyran ose (R)-S-Oxide (8a)
A) Th iolevoglucosan 2a (0.1 g, 0.56 m m ol) was dissolved in acetic acid (2 m l), an d aque-
ous solution of 10% h ydrogen peroxide (0.19 g, 0.56 m m ol) was added to it dropwise at
room tem perature. Th en th e reaction m ixture was kept at 0 °C for 3 h . Th e precipitated
crystallin e product was filtered off an d recrystallized from eth an ol to obtain 7a (0.07 g,
65%), m .p. 206–208 °C (decom p.), [α]D –121 (c 0.78, water), RF 0.09, RF (2a) 0.47 (eth yl ace-
tate–m eth an ol 9:1); ref.12 gives m .p. 231 °C (m eth an ol), [α]D –117 (water). For C6H10O5S
(194.2) calculated: 37.11% C, 5.19% H, 16.51% S; foun d: 37.05% C, 5.16% H, 16.54% S.
B) To a cooled (–5 °C) solution of th iolevoglucosan 2a (0.5 g, 2.8 m m ol) in m eth an ol
(15 m l) a solution of 0.6 g (3.48 m m ol) of 3-ch loroperoxyben zoic acid (75–80%) in m eth a-
n ol (5 m l) was added dropwise un der stirrin g an d coolin g with in 5 m in . Th en th e reaction
m ixture was stirred at room tem perature for 30 m in . Separated crystals of 7a (0.25 g, 46%)
were recrystallized from m eth an ol–eth yl acetate to give 0.2 g (36.7%) of pure 7a. Com bin ed
m oth er liquors were con cen trated to 1 m l volum e. TLC (eth yl acetate–m eth an ol 9:1)
revealed th e presen ce of 7a (RF 0.09) an d 8a (RF 0.26). Ch rom atograph ic separation on silica
gel (25 g, eth yl acetate–m eth an ol 97:3) gave 0.13 g (24%) of endo-sulfoxide 8a, wh ich was
crystallized from m eth an ol–eth yl acetate, m .p. 135–137 °C, [α]D –94 (c 0.77, water). For
C6H10O5S (194.2) calculated: 37.11% C, 5.19% H, 16.51% S; foun d: 36.96% C, 5.28% H,
16.31% S.
C) To 3 m l of an h ydrous tetrach lorom eth an e was added (S)-BINOL (7 m g, 0.0125 m m ol),
Ti(O-1-iPr)4 (0.0036 m l, 0.0125 m m ol) an d water (0.0045 m l, 0.25 m m ol). Th e m ixture was
stirred at room tem perature for 1 h , subsequen tly cooled to 0 °C an d th iolevoglucosan 2a
(100 m g, 0.5 m m ol) was added. After 30 m in , tert-butylh ydroperoxide (0.15 m l of 70% water
solution , 1 m m ol) was added dropwise an d th e reaction m ixture was stirred at 0 °C for 27 h .
Tetrach lorom eth an e was evaporated an d th e residue was separated by ch rom atograph y in
eth yl acetate–m eth an ol 1:1. endo-Sulfoxide 8a (105 m g, 97%) con tain ed on ly traces of 7a.
Crystal structure analysis of compound 8a. A colorless crystal of dim en sion s 0.4 × 0.35 ×
0.3 m m is orth orh om bic, space group P212121, C6H10O5S, M = 194.20, a = 6.3327(8) Å, b =
7.2541(9) Å, c = 16.478(3) Å, V = 756.97(19) Å3, Z = 4, Dx = 1.704 Mg m –3. All data were col-
lected on a Non ius MACHIII diffractom eter usin g m on och rom atized MoKα radiation (λ =
0.71069 Å) at 150(2) K. Absorption correction was n eglected (µ = 0.407 m m –1). A total of
1558 m easured reflection s in th e ran ge h = 0 to 7, k = 0 to 8, l = –19 to 19 (θm ax = 25°) out
of wh ich 1336 were un ique (Rin t = 0.0127) an d 1280 observed accordin g to th e I > 2σ(I) cri-
terion . Th e structure was solved by direct m eth ods (SIR92 41) an d refin ed by full-m atrix least
squares on F2 (SHELXL97 42). All n on -h ydrogen atom s were refin ed an isotropically. Th e h y-
drogen atom s on carbon s were calculated in to idealized position s an d con strain ed durin g re-
fin em en t (ridin g m odel) with assign ed displacem en t param eter Hiso(H) = 1.2Ueq(pivot atom ).
Th e h ydrogen atom s of h ydroxyls were foun d on differen ce m ap an d refin ed isotropically.
Th e refin em en t con verged (∆/σm ax = 0.001) to R = 0.024 for observed reflection s an d wR =
0.064, GOF = 1.098 for 121 param eters an d all 1336 reflection s. Th e fin al differen ce m ap
displayed n o peaks of ch em ical sign ifican ce (∆ρm ax = 0.242, ∆ρm in = –0.293. Th e absolute
con figuration was establish ed by th e an om alous dispersion effect, ch irality param eter 0.02(9).
CCDC 284672 (for 8a) con tain s th e supplem en tary crystallograph ic data for th is paper. Th ese
data can be obtain ed free of ch arge via www.ccdc.cam .ac.uk/con ts/retrievin g.h tm l (or from
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

1,6-Anhydro-1-thio-β-D-glucopyranose
333
th e Cam bridge Crystallograph ic Data Cen tre, 12, Un ion Road, Cam bridge, CB2 1EZ, UK; fax:
+44 1223 336033; or deposit@ccdc.cam .ac.uk).
2,3,4-Tri-O-acetyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (S)-S-Oxide (7b)
Sulfoxide 7a (0.3 g, 1.6 m m ol) was dissolved in dry pyridin e (30 m l) an d acetic an h ydride
(1.5 m l) was added. After 12 h th e crystallin e product was filtered off to obtain 7b (0.2 g, 40%);
th e secon d crop of 7b (0.275 g, 55%) was obtain ed from th e m oth er liquors. After crystalli-
zation from eth an ol–dieth yl eth er–petroleum eth er, com poun d 7b h ad m .p. 117–119 °C
(decom p.), [α]D –61 (c 0.55, CHCl3); ref.12 gives m .p. 122–123.5 °C, [α]D –75 (CHCl3). For
C
12H16O8S (320.3) calculated: 44.99% C, 5.03% H, 10.01% S; foun d: 45.22% C, 5.07% H,
9.79% S.
2,3,4-Tri-O-acetyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (R)-S-Oxide (8b)
Sulfoxide 8a (0.09 g) in pyridin e (5 m l) was treated dropwise with acetic an h ydride (1.5 m l)
an d th e reaction m ixture was left stan din g at 0 °C overn igh t. Th en ice water was added an d
th e reaction m ixture was extracted with dich lorom eth an e, th e organ ic layer was wash ed
with dilute h ydroch loric acid, sodium h ydrogen carbon ate an d water, an d dried over an h y-
drous MgSO4. After evaporation of th e solven t, th e solid residue was crystallized from eth yl
acetate–petroleum eth er to give 8b (80 m g, 54%), m .p. 114–116 °C, [α]D –133 (c 0.74,
CHCl3); ref.12 gives m .p. 119–120 °C, [α]D –149 (CHCl3). FAB MS, m/z: 321 [M + H+].
1,6-An h ydro-1-th io-β-D-glucopyran ose S-Dioxide (9a)
A solution of th iolevoglucosan (2a; 0.1 g, 0.56 m m ol) in acetic acid (0.2 m l) was treated
with 30% H2O2 (0.31 g, 2.74 m m ol) an d th e reaction was m on itored by TLC. After 5 days,
th e secon d portion of 30% H2O2 (0.31 g) was added an d th e reaction tim e was prolon ged
for an oth er 5 days. Durin g th e course of oxidation th e product 9a con tin uously precipitated
from th e reaction m ixture. Crystals were filtered off, wash ed with eth an ol an d dried to give
9a (0.023 g, 20%), m .p. ~ 200 °C (decom p.), [α]D –32 (c 0.8, water), RF 0.46, RF (7a) 0.12
(eth yl acetate–m eth an ol 9:1); ref.12 gives m .p. 208–209 °C, [α]D –40.6 (water). For C6H10O6S
(210.2) calculated: 34.28% C, 4.79% H, 15.25% S; foun d: 34.34% C, 4.82% H, 14.65% S.
Crystal structure analysis of compound 9a. A colorless crystal of dim en sion s 0.45 × 0.45 ×
0.2 m m is orth orh om bic, space group P212121, C6H10O6S, M = 210.20, a = 6.9660(2) Å, b =
10.4660(2) Å, c = 10.8700(3) Å, V = 792.49(4) Å3, Z = 4, Dx = 1.762 Mg m –3. Diffraction ex-
perim en t was carried on a Non ius KappaCCD diffractom eter usin g m on och rom atized MoKα
radiation (λ = 0.71069 Å) at room tem perature. Absorption correction was n eglected (µ =
0.405 m m –1). A total of 12390 m easured reflection s in th e ran ge h = –9 to 8, k = –13 to 13,
l = –14 to 14 (θm ax = 27.5°) out of wh ich 1813 were un ique (Rin t = 0.024) an d 1758 observed
41
accordin g to th e I > 2σ(I) criterion . Th e structure was solved by direct m eth ods (SIR92
)
an d refin ed by full-m atrix least squares on F2 (SHELXL97 42). All n on -h ydrogen atom s were
refin ed an isotropically. Th e h ydrogen atom s on carbon s were calculated in to idealized posi-
tion s an d con strain ed durin g refin em en t (ridin g m odel) with assign ed displacem en t param e-
ter Hiso(H) = 1.2Ueq(pivot atom ). Th e h ydrogen atom s of h ydroxyls were foun d on differen ce
m ap an d refin ed isotropically. Th e refin em en t con verged (∆/σm ax = 0.000) to R = 0.024 for
observed reflection s; wR = 0.064, GOF = 1.080 for 131 param eters an d all 1813 reflection s.
Th e fin al differen ce m ap displayed n o peaks of ch em ical sign ifican ce (∆ρm ax = 0.183, ∆ρm in
=
Collect. Czech. Chem. Commun. 2006, Vol. 71, No. 3, pp. 311–336

334
Buděšínský et al.:
–0.298. Th e absolute con figuration was establish ed by th e an om alous dispersion effect,
ch irality param eter 0.00(9). CCDC 284673 (for 9a) con tain s th e supplem en tary crystallo-
graph ic data for th is paper. Th ese data can be obtain ed free of ch arge via
www.ccdc.cam .ac.uk/con ts/retrievin g.h tm l (or from th e Cam bridge Crystallograph ic
Data Cen tre, 12, Un ion Road, Cam bridge, CB2 1EZ, UK; fax: +44 1223 336033; or
deposit@ccdc.cam .ac.uk).
2,3,4-Tri-O-acetyl-1,6-an h ydro-1-th io-β-D-glucopyran ose S-Dioxide (9b)
To a solution of th iolevoglucosan triacetate 2b (0.5 g, 1.6 m m ol) in acetic acid (1 m l), 30%
H2O2 (1.2 g, 10.6 m m ol) was added dropwise at 0 °C. Th e reaction m ixture was kept at room
tem perature for 4 days. Th en acetic acid was evaporated an d th e residue was crystallized
from eth an ol to give S-dioxide 9b (0.375 g, 70%), m .p. 167–169 °C, [α]D –11 (c 0.88,
CH2Cl2); ref.12 gives m .p. 181–182 °C, [α]D –21.7 (CHCl3). For C12H16O9S (336.3) calculated:
42.86% C, 4.76% H, 9.53% S; foun d: 42.96% C, 4.80% H, 9.58% S.
(6R)-6-C-Acetoxy-2,3,4-tri-O-acetyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (10)
Sulfoxide 7a (0.1 g, 0.52 m m ol) an d fused sodium acetate (0.05 g) were refluxed in acetic
an h ydride (5 m l) for 3 h . Th e reaction m ixture was poured in to ice water (20 m l), th e solu-
tion was n eutralized with sodium h ydrogen carbon ate an d was extracted with ch loroform
(3 × 10 m l). Th e organ ic layer was separated, dried an d filtered th rough a sh ort colum n of
silica gel. Th en th e solven t was evaporated un der reduced pressure (oil pum p) to obtain a
colorless syrupy com poun d 10 (0.17 g, 61%) wh ich was pure accordin g to TLC (RF 0.84,
RF (7a) 0.07) in aceton e–ben zen e–eth yl acetate –water 4:1:2:2, [α]D –156 (c 1.0, CHCl3); ref.12
gives [α]D –218 (CHCl3). For C14H18O9S (362.4) calculated: 46.41% C, 5.61% H, 8.85% S;
foun d: 46.49% C, 5.18% H, 9.07% S.
2,4-Di-O-ben zoyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (11) an d
2,3,4-Tri-O-ben zoyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (12)
To a stirred an d cooled (–5 °C) solution of th iolevoglucosan 2a (1 g, 5.6 m m ol) in pyridin e
(15 m l) ben zoyl ch loride (1.6 g, 10 m m ol) in aceton e (2 m l) was added dropwise. Th en th e
tem perature was allowed to warm to room tem perature. After 12 h TLC (ben zen e–aceton e
10:1) revealed product 11 an d a sm all am oun t of startin g com poun d. An oth er portion of
ben zoyl ch loride (0.8 g, 5 m m ol) in aceton e (1 m l) was added an d th e reaction m ixture was
left stan din g at room tem perature for an oth er 5 h . Th e reaction m ixture was th en poured
in to a cold aqueous solution of NaHCO3, extracted with ch loroform , an d th e organ ic layer
was evaporated to obtain a syrup. After addin g eth er to it, a solid precipitated an d was crys-
tallized from ch loroform –dieth yl eth er to give 12 (1.22 g, 44%), m .p. 169–172 °C, [α]D –22
(c 0.85, CHCl3); ref.10 gives m .p. 168–170 °C, [α]D –31.5 (c 0.54, CHCl3). For C27H22O7S
(490.5) calculated: 66.11% C, 4.52% H, 6.54% S; foun d: 65.80% C, 4.52% H, 6.64% S.
Moth er liquors were evaporated an d th e syrupy residue was separated on a silica gel colum n
(ben zen e–aceton e 10:1) to obtain a secon d portion of th e triben zoate 12 (1.27 g, 46%) an d
2,4-di-O-ben zoyl derivative 11 (0.085 g, 4%), m .p. 123–124 °C, [α]D –16 (c 1.9, CHCl3); ref.10
gives m .p. 124–126 °C, [α]D –24.6 (c 0.32, CHCl3). For C20H18O6S (386.4) calculated:
62.16% C, 4.69% H, 8.30% S; foun d: 61.95% C, 4.76% H, 8.52% S.
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1,6-Anhydro-1-thio-β-D-glucopyranose
335
2,4-Di-O-ben zoyl-3-O-m esyl-1,6-an h ydro-1-th io-β-D-glucopyran ose (13)
To a cool solution (<0 °C) of 2,4-di-O-ben zoyl derivative 11 (0.056 g, 0.14 m m ol) in dry
pyridin e (1 m l), m esyl ch loride (0.017 g, 0.15 m m ol) in pyridin e (0.5 m l) was added. After
12 h , th e m ixture was poured in to ice water. After 1 h , th e crystallin e product was filtered
off an d recrystallized from aqueous eth an ol to obtain 13 (0.04 g, 87%), m .p. 164–166 °C,
[α]D –33 (c 0.55, CHCl3). MS, m/z: 464.2 [M+].
We thank Dr M. Štícha for mass spectra measurement, Mgr B. Šperlichová for the optical rotations
measurement, and the Analytical Department of the Institute of Organic Chemistry and Biochemistry
of the Academy of Sciences of the Czech Republic, Prague for elemental analysis.
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