Table 5.
| ||||||
---|---|---|---|---|---|---|
entry | R | product | time (h) | C-4:C-6a | α:βa | yield (%) |
1 | -CH2CH3 | 8a | 6 | 5:>95 | 12:88 | 42 |
2 | -CH3 | 8b | 8 | 8:92 | 10:90 | 39 |
3 | -CH2Ph | 8c | 12 | 5:>95 | 5:>95 | 61 |
4 | -C(CH3) | 8d | 10 | 5:>95 | 5:>95 | 46 |
5 | -(CO)CH3 | 8e | 16 | - | - | <5 |
Ratio determined by 1H NMR spectroscopy of the crude reaction mixture. All reactions were run at a concentration of 0.15 M with respect to 2.
Isolated yield of the 8-β diastereomer