Table 1. Results of the Substitution Reaction of TES-d with the 4-Oxo- and 4-Thiofuranosides.
X = O | X = S |
||
---|---|---|---|
α/β ratio (exp)ab | α/β ratio (comp) | α/β ratio (exp)cb | |
riboside | >98:2 | 94:6 | 91:9 |
arabinoside | <2:98 | 2:98 | 8:92 |
xyloside | 85:15 | 68:32 | 69:31 |
lyxoside | <2:98 | 0:100 | 3:97 |
Reagents and conditions: 2 equiv of TES-d, 1.3 equiv of TMSOTf, −78 °C, 7 days.
The α/β ratio was established by NMR spectroscopy.
Reagents and conditions: 2 equiv of TES-d, 1.3 equiv of TMSOTf, −30 °C, 10 days.