|
|
wt/vol
|
MW/conc.
|
Moles
|
density
|
equivs.
|
yield
|
|
I
|
1.840 g
|
300.55
|
0.0061
|
|
1.0
|
|
|
II
|
18.3 mL
|
1.0 M
|
0.0183
|
|
3.0
|
|
|
III
|
40 mL
|
-
|
-
|
|
|
|
|
IV
|
1.038 g
|
186.29
|
0.0056
|
|
|
(91%)
|
Procedure: 100 mL
1-neck flask, stirbar, cap
Dissolved
1.840 g alcohol I in 40 mL of THF. Stirred at rt. Added 18.3 mL of TBAF (1.0 M in THF,
water content ~5 wt. %, Aldrich).
After 3 h, quenched with sat. aq. NH4Cl. Extracted with EtOAc. The organic layer was dried over MgSO4,
filtered and the solvent was removed by rotary evaporation. The product was isolated by flash
chromatography on silica gel using 75:25 Et2O-hexanes. The product was a clear, pale yellow
oil.
1H NMR (CDCl3,
400 MHz) d 5.76 (dq, J = 15.4, 6.5 Hz, H2), 5.46 (ddq, J = 15.3, 7.3, 1.6 Hz, H3), 3.83 (m, H4), 3.41 (m, H5),
2.11 (b, OH), 2.02 (b, OH), 1.71 (dd, J = 6.5, 1.1 Hz, H1), 1.53-1.22 (m, CH2s), 0.86 (t,
J = 7.0 Hz, H11).