Notes
(3a r,6r,6a r)- a n d (3a r,6â,6a r)-H exa h yd r o-6-[2-[(t r i-
J . Org. Chem., Vol. 62, No. 20, 1997 7031
and AIBN (9 mg, 0.055 mmol) in dry PhH (0.9 mL), contained
in a Pyrex test tube (1 × 10 cm) closed by a septum, was
degassed with a vigorous stream of Ar, which was passed
through the solution for 6 min. The mixture was then irradiated
for 12 h at room temperature (Hanovia, 140 W). The resulting
cloudy solution was evaporated, and flash chromatography of
the residue over silica gel (1.5 × 15 cm), using 2.5:97.5 EtOAc-
hexane (containing 1% Et3N), gave 10a (61.0 mg, 72%) as a
colorless oil: FTIR (benzene cast) 856 cm-1; 1H NMR (C6D6, 400
MHz) δ 0.02 (s, 9 H), 1.49 (br s, 2 H), 1.50-1.70 (m, 4 H), 1.96
(t, J ) 7.28 Hz, 2 H), 3.15 (s, 6 H), 4.33 (t, J ) 5.5 Hz, 1 H), 4.64
(br s, 1 H), 4.74 (br s, 1 H); 13C NMR (benzene-d6, 75.5 MHz) δ
-1.28 (q′), 23.24 (t′), 26.75 (t′), 32.52 (t′), 38.36 (t′), 52.18 (q′),
104.58 (d′), 107.71 (t′), 147.32 (s′). A satisfactory mass spectrum
(EI, CI, and FAB) could not be obtained.
Dih yd r o-5-[3-[(tr im eth ylsilyl)m eth yl]-3-bu ten yl]-2(3H)-
fu r a n on e (11a ). Iodo lactone 1126 (98.7 mg, 0.436 mmol) and
4a (395.6 mg, 0.873 mmol) were weighed into a Pyrex test tube
(1 × 10 cm). The tube was closed with a rubber septum, kept
under vacuum for 10 min, and then filled with Ar. Dry PhH (1
mL) was added, and the mixture was irradiated (Hanovia, 140
W) for 17 h, exactly as described for 8. Evaporation of the
solvent and flash chromatography of the residue over silica gel
(1.5 × 23 cm), using 1:9 acetone-hexane, and again over silica
gel (1 × 20 cm), using, 1:9 EtOAc-hexane, gave 11a 27 (74.3 mg,
75%) as a colorless oil: FTIR (benzene cast) 1777 cm-1; 1H NMR
(C6D6, 400 MHz) δ 0.0 (s, 9 H), 0.92-1.05 (m, 1 H), 1.25-1.40
(m, 2 H), 1.42 (br s, 2 H), 1.48-1.60 (m, 1 H), 1.75-2.02 (m, 4
H), 3.75-3.85 (m, 1 H), 4.59-4.64 (m, 2 H); 13C NMR (benzene-
d6, 75.5 MHz) δ -1.36 (q′), 26.93 (t′), 27.73 (t′), 28.52 (t′), 33.98
(t′), 34.06 (t′), 79.26 (d′), 107.80 (t′), 146.40 (s′), 175.44 (s′); exact
mass, m/ z calcd for C12H22O2Si 226.13892, found 226.13824.
m eth ylsilyl)m eth yl]-2-p r op en yl]-2H-cyclop en ta [b]fu r a n -2-
on e (8a ). Iodo lactone 824 (159 mg, 0.63 mmol) and 4a (608
mg, 1.46 mmol) were weighed into a Pyrex test tube (1 × 10
cm). The tube was closed with a rubber septum, kept under oil
pump vacuum for 10 min, and then filled with Ar. This
procedure was repeated once more, and dry PhH (1 mL) was
then added. The tube was mounted in a slanting position with
its base immersed in a water bath kept at 15 to 20 °C and
irradiated (Hanovia, 140 W) for 15 h (Ar atmosphere). Evapora-
tion of the solvent and flash chromatography of the residue over
silica gel (2 × 25 cm), using 5:95 acetone-hexane, gave 8a (108
mg, 68%) as an inseparable 9.3:1 mixture (1H NMR) of isomers:
FTIR (benzene cast) 1776 cm-1; 1H NMR (C6D6, 400 MHz) δ 0.0
(s, 9 H), 0.80-1.0 (m, 2 H), 1.35-1.49 (m, 3 H) 1.50-1.70 (m, 2
H), 1.71-1.90 (m, 2 H), 1.91-2.25 (m, 3 H), 4.11 (dd, J ) 6.9,
2.3 Hz, 1 H), 4.63 (s, 2 H); 13C NMR (benzene-d6, 75.5 MHz)
(peaks for the minor isomer are indicated by an asterisk) δ -1.31
(q′), -0.97 (q′)*, 26.19 (t′), 27.29 (t′)*, 28.99 (t′)*, 29.85 (t′), 31.62
(t′), 32.49 (t′)*, 35.52 (t′), 36.34 (t′)*, 37.37 (d′)*, 37.65 (d′), 37.73
(t′)*, 41.04 (t′), 43.93 (d′), 44.74 (d′)*, 86.06 (d′)*, 89.48 (d′), 108.40
(t′)*, 109.41 (t′), 145.40 (s′), 146.12 (s′)*, 175.83 (s′) (several of
the peaks coincide); exact mass, m/ z calcd for C14H24O2Si
252.15456, found 252.15378.
Met h yl 4-[2-[(Tr im et h ylsilyl)m et h yl]-2-p r op en yl]b en -
zoa te (9a ). A solution of 9 (100 mg, 0.38 mmol), 4a (638.5 mg,
1.53 mmol), and 1,1′-azobis(cyclohexanecarbonitrile) (19 mg,
0.076 mmol) in dry DME (0.8 mL), contained in a Pyrex test
tube (1 × 10 cm) closed by a septum, was degassed with a
vigorous stream of Ar, which was passed through the solution
for 6 min. The mixture was then irradiated for 24 h at room
temperature (Rayonet, 3000 Å). The resulting cloudy mixture
was diluted with Et2O (2 mL), and DBU (3 drops) was added
with shaking. The resulting solid was filtered off and washed
with Et2O. Evaporation of the filtrate and flash chromatography
of the residue over silica gel (1.5 × 23 cm), using 1:4:200 Et3N-
EtOAc-hexane, gave a mixture of 9a and methyl benzoate (75
mg). The material contained 51 mol % 9a and 47 mol % methyl
benzoate as judged by its 1H NMR (360 MHz) spectrum.
In another experiment, a sample of 9a was obtained as a
colorless oil by flash chromatography over silica gel, using 1.5:
Meth yl 2,3,4-Tr i-O-a cetyl-6,7,8,9-tetr a d eoxy-8-[(tr im eth -
ylsilyl)m eth yl]-r-D-glu co-n on -8-en op yr a n osid e (13a ). (a )
Use of 4a . Methyl 2,3,4-tri-O-acetyl-6-deoxy-6-iodo-R-D-glu-
copyranoside28 (13) (100 mg, 0.23 mmol), AIBN (3.8 mg, 0.023
mmol), and 4a (384.8 mg, 0.92 mmol) in dry DME (1 mL),
contained in a Pyrex test tube (1 × 10 cm) closed by a septum,
was degassed with a vigorous stream of Ar, which was passed
through the solution for 6 min. The mixture was then irradiated
(Hanovia, 140 W) for 9 h at 15-20 °C (cold water bath). The
resulting cloudy solution, containing some white precipitate, was
diluted with Et2O (2 mL), and DBU (3 drops) was added with
shaking. The solid was filtered off and washed with Et2O.
Evaporation of the filtrate and flash chromatography of the
residue over silica gel (1.5 × 23 cm), using 1:4 EtOAc-hexane,
gave methyl 2,3,4-tri-O-acetyl-6-deoxy-R-D-glucopyranoside29 (13b)
(36 mg, 51%) as a colorless oil. The fraction containing 13a was
rechromatographed over silica gel (0.5 × 14 cm), using 2:98
Et2O-CH2Cl2, to give 13a (45.4 mg, 45%) as a colorless oil.
1
98.5 EtOAc-hexane: FTIR (hexane cast) 1725 cm-1; H NMR
(acetone-d6, 400 MHz) δ 0.05 (s, 9 H), 1.52 (s, 2 H), 3.38 (s, 2 H),
3.86 (s, 3 H), 4.60 (br s, 1 H), 4.66 (br s, 1 H), 7.34 (br d, J )
8.34 Hz, 2 H), 7.94 (br d, J ) 8.34 Hz, 2 H); 13C NMR (acetone-
d6, 75.5 MHz) δ -1.21 (q′), 26.66 (t′), 45.44 (t′), 52.17 (q′), 110.33
(t′), 129.16 (s′), 130.13 (d′), 130.21 (d′), 146.39 (s′), 147.22 (s′),
167.18 (s′); exact mass, m/ z calcd for C15H22O2Si 262.13892,
found 262.13842.
1-Iod o-3,3-d im eth oxyp r op a n e (10). The literature proce-
dure for the corresponding ethylene ketal25 was followed, with
some modifications. Freshly distilled Me3SiCl (15.3 mL, 120
mmol) was added over 1 min to a stirred and cooled (0 °C)
solution of acrolein (6.7 mL, 100 mmol) and dry NaI (18 g, 120
mmol) in dry MeCN (250 mL). The resulting yellow solution
was stirred for 5 min, and then dry MeOH (9.72 mL, 240 mmol)
was added in one portion. Stirring was continued for 5 min,
and the solution was then poured into 5% saturated aqueous
NaHCO3 (100 mL) overlaid with pentane (300 mL). The mixture
was shaken, and the bottom layer was removed. The residual
two organic phases were washed with 5% aqueous Na2S2O3 (80
mL) and then with brine (7 × 100 mL), at which point only the
top layer remained. The organic extract was dried (K2CO3) and
evaporated. The residual oil was dissolved in pentane (20 mL)
and filtered through a short column of basic, grade 3 alumina
(3 × 8 cm), using pentane (100 mL). Evaporation of the filtrate
gave 10 (13.9 g, 60%) as an oil: FTIR (CH2Cl2 cast) 2988, 2952,
2935, 2908, 2830, 1458, 1443 cm-1; 1H NMR (400 MHz, CDCl3)
2.04-2.11 (m, 2 H), 3.12 (t, J ) 7 Hz, 2 H), 3.31, (s, 6 H), 4.42
(t, J ) 5.5 Hz, 1 H); 13C NMR (100.6 MHz, CDCl3) δ -0.14 (t′),
36.47 (t′), 53.51 (q′), 104.42 (d′); exact mass, m/ z calcd for
C5H11IO2 229.98038, found 229.98022. A satisfactory combus-
tion analysis could not be obtained.
Compound 13a : FTIR (CH2Cl2 cast) 1754, 1633, 1225 cm-1
;
1H NMR (C6D6, 360 MHz) δ 0.03 (s, 9 H), 1.51 (s, 2 H), 1.61-
1.85 (m, 11 H), 1.98-2.08 (m, 1 H), 2.27-2.34 (m, 1 H), 2.99 (s,
3 H), 3.75-3.81 (m, 1 H), 4.65 (s, 1 H), 4.75 (dd, J ) 2.8, 1.3 Hz,
1 H), 4.88 (d, J ) 3.7 Hz, 1 H), 5.07 (dd, J ) 10.3, 3.7 Hz, 1 H),
5.14 (dd, J ) 9.9, 9.4 Hz, 1 H), 5.88 (dd, J ) 10.3, 9.4 Hz, 1 H);
13C NMR (C6D6, 75.5 MHz) δ -1.32 (q′), 20.21 (q′), 20.37 (q′),
26.94 (t′), 29.87 (t′), 33.86 (t′), 54.86 (q′), 68.35 (d′), 70.84 (d′),
71.69 (d′), 72.77 (d′), 96.99 (d′), 107.88 (t′), 146.94 (s′), 169.35
(s′), 169.68 (s′), 169.75 (s′); exact mass, m/ z calcd for C20H34O8Si
430.20230, found 430.20232.
Meth yl 2,3,4-tr i-O-a cetyl-6-d eoxy-r-D-glu cop yr a n osid e29
(13b): FTIR (CH2Cl2 cast) 1751, 1248, 1225 cm-1 1H NMR
;
(CDCl3, 300 MHz) δ 1.19 (d, J ) 6.3 Hz, 3 H), 2.00 (s, 3 H), 2.03
(s, 3 H), 2.06 (s, 3 H), 3.38 (s, 3 H), 3.82-3.95 (m, 1 H), 4.79 (dd,
J ) 9.6, 9.6 Hz, 1 H), 4.83-4.89 (m, 2 H), 5.39-5.46 (m, 1 H);
13C NMR (CDCl3, 75.5 MHz) δ 17.19 (q′), 20.69 (q′), 55.24 (q′),
64.90 (d′), 70.07 (d′), 71.23 (d′), 73.80 (d′), 96.59 (d′), 169.84 (s′),
(26) Cambie, R. C.; Hayward, R. C.; Roberts, J . L.; Rutledge, P. S.
J . Chem. Soc. 1974, 32, 1864.
(27) Reaction with the corresponding bromide (Cambie, R. C.;
Rutledge, P. S.; Somerville, R. F.; Woodgate, P. D. Synthesis 1988,
1009) gave 11a in only 6% yield.
(28) Garegg, P. J .; Samuelsson, B. J . Chem. Soc., Perkin Trans. 1
1980, 2866.
[2-(4,4-Dim eth oxybu tyl)-2-pr open yl]tr im eth ylsilan e (10a).
A solution of 10 (84.3 mg, 0.367 mmol), 4a (311 mg, 0.75 mmol),
(24) Clive, D. L. J .; Kale`, V. J . Org. Chem. 1981, 46, 231.
(25) Larsen, G. L.; Kleese, R. J . Org. Chem. 1985, 50, 3627.
(29) Roberts, E. V. E.; Schwarz, J . C. P.; McNab, C. A. Carbohydr.
Res. 1968, 7, 311.