W.-B. Yang et al. / Tetrahedron 58 -2002) 253±259
257
3.47±3.63 :m, 3H, H-6a, H-6b, H-4), 3.66 :ddd, 1H, J
11.0, 4.9, 3.0 Hz, H-5), 3.76 :dd, 1H, J9.2, 4.5 Hz,
H-1a), 3.91 :dt, 1H, J9.2, 4.5 Hz, H-2), 3.95 :s, 1H,
OH), 4.00 :d, 1H, J4.5 Hz, H-1b), 4.05 :t, 1H, J
7.5 Hz, H-3); 13C NMR :125 MHz, CDCl3) d 25.25,
25.25, 25.20, 25.09, 24.21, 23.91, 23.63, 23.63,
17.82, 18.06, 18.20, 18.47, 25.74, 25.85, 25.89, 26.08,
62.79, 63.57, 69.36, 70.14, 73.09, 73.70; ESI-MS m/z :rel.
intensity): 639 :M1H1, 100), 507 :7); HRMS :FAB) calcd
for C30H71O6Si4 :M1H1) 639.4328, found 639.4329.
Finely powdered d-glucono-1,5-lactone :1.78 g, 10.0
mmol) was dissolved in an acetone solution :50 mL)
containing I2 :507.6 mg, 2.0 mmol). The reaction was
stirred at 458C for 24 h. The solvent was removed under
reduced pressure to give a residue, which was chromato-
graphed by a silica gel column with EtOAc/hexanes :1/1)
to give a mixture of compounds 7c and 7d. Compound 7c
was crystallized, and its structure was con®rmed by an
X-ray diffraction analysis. The mother liquor was further
subjected to chromatography on a silica gel column
:EtOAc/hexanes1/3) to afford pure compounds 7c and
1
4.1.5. 2,3,4-Tri-O-tert-butyldimethylsilyl-d-glucitol )6).
Boron trichloride :0.1 mL of 1 M solution in CH2Cl2) was
added to a CH2Cl2 solution :5 mL) of compound 4 :100 mg,
0.15 mmol) at 2788C. The reaction progress was monitored
by TLC with hexanes/EtOAc :5/1). The reaction was stirred
at 2788C for 5 min, after which the reaction mixture was
neutralized with saturated NaHCO3 solution. The resulting
mixture was extracted with CH2Cl2, dried over anhydrous
Na2SO4, and concentrated. The residue was subjected to
silica gel chromatography with hexanes/EtOAc :5/1) to
give 67 mg of diol 5 in 70% yield and 17 mg of triol 6 in
20% yield. Compound 6: Rf0.45 :EtOAc/hexanes1/4);
1H NMR :400 MHz, CDCl3) d 0.05 :s, 3H, SiCH3), 0.05 :s,
3H, SiCH3), 0.09 :s, 9H, SiCH3), 0.10 :s, 3H, SiCH3), 0.11
:s, 3H, SiCH3), 0.12 :s, 3H, SiCH3), 0.88 :s, 9H, C:CH3)3),
0.89 :s, 9H, C:CH3)3), 0.90 :s, 9H, C:CH3)3), 2.29 :br s, 1H,
OH), 3.03 :br s, 1H, OH), 3.47 :br s, 1H, OH), 3.56 :dd, 1H,
J10.2, 4.7 Hz, H-1a), 3.63 :dd, 1H, J11.2, 5.5 Hz, H-6a),
3.65 :dd, 1H, J11.2, 3.7 Hz, H-1b), 3.70 :dd, 1H, J8.7,
5.6 Hz, H-3), 3.76 :dd, 1H, J10.2, 5.6 Hz, H-1b), 3.80 :m,
1H, H-5), 3.88 :t, 1H, J5.6 Hz, H-4), 3.93 :ddd, 1H, J
8.7, 5.6, 4.7 Hz, H-2); 13C NMR :100 MHz, CDCl3) d
25.52, 25.43, 24.68, 24.62, 24.26, 23.98, 18.12,
18.18, 18.30, 25.85, 25.91, 25.93, 63.60, 65.39, 71.79,
72.83, 73.04, 73.82; ESI-MS m/z :rel. intensity): 525.2
:M1H1, 100), 393.2 :5); HRMS :FAB) calcd for
C24H57O6Si3 :M1H1) 525.3463, found 525.3485.
7d. Compound 7c: H NMR :400 MHz, CDCl3) d 1.33 :s,
3H, CH3), 1.37 :s, 3H, CH3), 1.40 :s, 3H, CH3), 1.42 :s, 3H,
CH3), 3.98 :dd, J3.7, 8.0 Hz, 1H, H-6), 4.01 :dd, J7.9,
8.0 Hz, 1H, H-4), 4.09 :ddd, J2.1, 3.7, 8.0 Hz, 1H, H-5),
4.13 :dd, J2.1, 8.0 Hz, 1H, H-6), 4.29 :dd, J1.4, 7.9 Hz,
1H, H-3), 4.40 :d, J1.4 Hz, 1H, H-2). Crystallographic
data of 7c have been deposited with the Cambridge Crystal-
lographic Data Center as the deposition number CCDC
173783. Copies of the data can be obtained, free of charge,
on application to CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK :fax: 144:0)-1223-336033 or e-mail: deposit@
ccdc.cam.ac.uk). Compound 7d: 1H NMR :400 MHz,
CDCl3) d 1.31 :s, 3H, CH3), 1.37 :s, 3H, CH3), 1.37 :s,
3H, CH3), 1.39 :s, 3H, CH3), 1.54 :s, 3H, CH3), 1.63 :s,
3H, CH3), 3.92 :t, J8.4 Hz, 1H, H-4), 3.96 :dd, J3.9,
8.2 Hz, 1H, H-6), 4.07 :ddd, J3.9, 6.0, 8.4 Hz, 1H, H-5),
4.12 :dd, J6.0, 8.2 Hz, 1H, H-6), 4.25 :dd, J1.5, 8.4 Hz,
1H, H-3), 4.60 :d, J1.5 Hz, 1H, H-2).
4.1.8. 2,3-Di-O-tert-butyldimethylsilyl-d-glucono-1,4-lac-
tone )8),19 methyl l-glycerate )10),20 and 1,2-O-isopropyl-
idene-a-d-glucofuranose )12).21 Compound 3b :35.2 mg,
0.079 mmol) and tin:II) chloride :70 mg, 0.37 mmol) were
mixed in anhydrous CH2Cl2 :2 mL), and stirred at room
temperature. The reaction progress was monitored by TLC
with CHCl3/MeOH :5/1). After 48 h, the mixture was
evaporated and puri®ed by silica gel chromatography with
CHCl3/MeOH :5/1) to give 27.3 mg of diol 8 in 85% yield
25
4.1.6. Methyl 2,3:5,6-di-O-isopropylidene-d-gluconate
)7a)16 and methyl 3,4:5,6-di-O-isopropylidene-d-gluco-
nate )7b).17 As previously mentioned in the main text,
compounds 7a and 7b were obtained as the side products
in the reaction of d-glucono-1,5-lactone with 2,2-dimethoxy-
propane and tin:II) chloride. Compound 7a: 1H NMR
:400 MHz, CDCl3) d 1.32 :s, 3H, CH3), 1.38 :s, 3H,
CH3), 1.43 :s, 3H, CH3), 1.46 :s, 3H, CH3), 2.15 :d, J
9.4 Hz, 1H, OH), 3.63 :ddd, J9.4, 8.5, 1.9 Hz, 1H, H-4),
3.76 :s, 3H, OMe), 4.03±3.98 :m, 1H, H-5), 4.10±4.05 :m,
2H, H-6), 4.39 :dd, J1.9, 7.7 Hz, 1H, H-3), 4.53 :d,
as a white solid. Rf0.6 :CHCl3/MeOH5/1); [a]D
1
134.08 :c 0.51, CHCl3); H NMR :400 MHz, CDCl3) d
0.14 :s, 3H, SiCH3), 0.15 :s, 3H, SiCH3), 0.15 :s, 6H,
SiCH3), 0.89 :s, 9H, C:CH3)3), 0.90 :s, 9H, C:CH3)3), 2.59
:d, J5.4 Hz, 1H, OH), 3.76 :dd, J4.9, 11.3 Hz, 1H, H-6),
3.87 :dd, J2.4, 11.3 Hz, 1H, H-6), 3.99 :m, 1H, H-5), 4.09
:d, J2.9 Hz, 1H, H-2), 4.30 :dd, J2.9, 4.0 Hz, 1H, H-3),
4.50 :dd, J4.0, 8.9 Hz, 1H, H-4); 13C NMR :100 MHz,
CDCl3) d 25.03, 25.01, 24.72, 24.65, 17.96, 18.08,
25.59, 25.61, 63.71, 68.63, 74.70, 74.94, 79.88, 173.69.
HRMS :FAB) calcd for C18H39O6Si2 :M1H1) 407.2285,
found 407.2282. By similar procedures, deprotection of
compounds 9 and 11 gave compounds 10 and 12 in 88
and 93% yields, respectively. Compound 10: 1H NMR
:400 MHz, CDCl3) d 4.25 :bs, 1H), 3.96±3.77 :m, 2H),
3.76 :s, 3H, ±OMe), 3.34 :bs, 1H, ±OH), 2.63 :bs, 1H,
±OH); 13C NMR :100 MHz, CDCl3) d 52.64, 64.01,
71.79, 173.41; 13C NMR :100 MHz, CD3OD) d 51.29,
63.72, 71.99, 173.29. FAB-MS calcd for C4H9O4 :M1H1)
1
J7.7 Hz, 1H, H-2). Compound 7b: H NMR :400 MHz,
CDCl3) d 1.32 :s, 3H, CH3), 1.33 :s, 3H, CH3), 1.36 :s, 3H,
CH3), 1.40 :s, 3H, CH3), 2.99 :d, J9.1 Hz, 1H, OH), 3.81
:s, 3H, OMe), 3.96 :dd, J3.9, 8.2 Hz, 1H, H-6), 4.03 :d,
1H, J7.5 Hz, 1H, H-2), 4.06 :ddd, J3.9, 5.6, 9.0 Hz, 1H,
H-5), 4.12 :dd, J5.6, 8.2 Hz, 1H, H-6), 4.19 :dd, J1.5,
7.5 Hz, 1H, H-3), 4.31 :dd, J1.5, 9.0 Hz, 1H, H-4); 13C
NMR :100 MHz, CHCl3) d 25.25, 26.51, 26.65, 27.14,
52.64, 67.87, 69.44, 76.48, 77.27, 80.89, 109.85, 110.06,
172.97.
1
121.0, found 121.1. Compound 12: H NMR :400 MHz,
DMSO-d6) d 1.21 :s, 3H, CH3), 1.36 :s, 3H, CH3), 3.34
:m, 1H, H-6), 3.55 :ddd, J3.0, 5.4, 11.2 Hz, 1H, H-6),
3.68 :m, 1H, H-5), 3.82 :dd, J2.4, 8.5 Hz, 1H, H-4),
4.02 :bs, 1H, H-3), 4.36 :d, J3.6 Hz, 1H, H-2), 4.48 :m,
4.1.7. 3,4:5,6-Di-O-isopropylidene-d-glucuronic acid )7c)
and 1,2:3,4:5,6-tri-O-isopropylidene-d-gluconate )7d).18