Table 4.
| ||||||
---|---|---|---|---|---|---|
entry | R | product | time (h) | C-4:C-6a | α:βa | yield (%)b |
1 | -CH2CH3 | 7a | 4 | 10:90 | 15:85 | 41 |
2 | -CH3 | 7b | 4 | 8:92 | 12:88 | 46 |
3 | -CH2Ph | 7c | 6 | 5:>95 | 22:78 | 39 |
4 | -C(CH3) | 7d | 3 | 5:>95 | 8:92 | 70 |
5 | -(CO)CH3 | 7e | 4 | 5:>95 | 5:>95 | 66 |
6 | -(CO)CH2CH3 | 7f | 10 | 5:>95 | 11:89 | 71 |
7 | -(CO)CH2Ph | 7g | 6 | 5:>95 | 5:>95 | 38 |
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 7-β diastereomer