Table 1.
Entry | Condition | Yield (%) a | ||
---|---|---|---|---|
16 | 13 | 17 | ||
1 | H2, Pd/C, MeOH, rt | - b | 99 | - |
2 | NaBH4 (1.5 eq), EtOH, rt | - | - | <10 |
2 | NaBH4 (2.5~5.0 eq), EtOH, rt | - | - | 50 |
3 | DIBAL c (1.0 eq), THF:toluene (1:1), −60 °C | 20 | - | 20 |
4 | LiAlH4 (2.0 eq), THF:Et2O (1:1), −60 °C | 99 | - | - |
a Isolated yield; b not found; c diisobutylaluminum hydride.