Table 4.
Gold-catalyzed Dehydrative Spirocyclization of Triols 6.
| |||||||
|---|---|---|---|---|---|---|---|
| entry | 6 | R1 | R2 | n | [Au] | time (h) | 7/yielda (%) |
| 1 | 6a | Ph | H | 0 | Ph3PAuCl | 5 | 7a (89) |
| 2 | 6b | Ph | Me | 0 | Ph3PAuCl | 4 | 7b (11) |
| 3 | 6b | Ph | Me | 0 | Bb | 4 | 7b (22)c |
| 4 | 6b | Ph | Me | 0 | Cd | 4 | 7b (46) |
| 5 | 6c | H | Me | 1 | Ph3PAuCl | 12 | 7c (64)e |
Isolated yield.
B = [c-Hex2(o-biphenyl)]PAuCl.
40 °C.
C = [t-Bu2(o-biphenyl)]PAuCl.
19% reisolated starting material.