Table 3.
Investigation of concurrent changes of DKR parameters with 7 as acyl donor.a
 | |||||||
| Entry | Ethyl methoxyacetate (7) (equiv) | Hydrogen donor 9 (mmol) | CALB/Na2CO3 (mg) | ee (%) | Yield (%)b | ||
| 0 h | 24 h | 48 h | |||||
| 1 | 1.5 | — | — | 2.5 | 20/40 | 83 | 99 |
| 2 | 1 | 0.5 | — | 2.5 | 20/40 | 86 | 79 |
| 3 | 1 | 0.5 | — | 2.5 | 10/20 | 90 | 97 |
| 4d | 1 | 0.5 | — | 1 | 20/40 | 74 | 88 |
| 5c | 1 | 0.1 | — | 1 | 20/40 | 97 | 87 |
| 6c | 1 | — | 0.2 | 1 | 20/40 | 96 | 83 |
| 7 | 1 | 0.15 | — | 1.25 | 10/20 | 95 | 70 |
| 8e | 1 | 0.15 | — | 2.5 | 10/20 | 97 | 91 |
| 9 | 0.75 | 0.35 | — | 2.5 | 10/20 | 94 | 73 |
aConditions: 1 mmol of 1, 1 mol % of 4, 10 mg of CALB, 20 mg of Na2CO3, ethyl methoxyacetate (7), 2.5 mmol of hydrogen donor 9, 5 mL of toluene, 90 °C, 72 h; bdetermined by GC; c10 mL of toluene; d2 mL of toluene; e100 °C.