Table 3.
Entry | R | R' | M | Yield (%) | 38 : 39 | Ref. |
---|---|---|---|---|---|---|
1 | OEt | C6H5 | Li | 85 | 92 : 08 | 43a |
2 | OEt | C6H5 | Na | 80 | 96 : 04 | 43a |
3 | OEt | 4-MeOC6H4 | Li | 50 | 92 : 08 | 43a |
4 | OEt | 4-MeOC6H4 | Na | 50 | 95 : 05 | 43a |
5 | OEt | n-Pr | Li | 78 | 92 : 08 | 43b |
6 | Oi-Pr | C6H5 | Li | 82 | 74 : 26 | 46b |
7 | Oi-Pr | 4-MeOC6H4 | Li | 55 | 93 : 07 | 46b |
8 | Oi-Pr | n-Pr | Na | 86 | 99 : 01 | 43b |
9 | OMe | C6H5 | Na | a | 88 : 12 | 46a |
10 | OMe | C6H5 | Li | a | 94 : 06 | 46a |
11 | OMe | 2-furyl | Li | a | 94 : 06 | 46b |
12 | OMe | 2-thienyl | Li | a | 95 : 05 | 46b |
13 | NEt2 | C6H5 | Li | a | 10 : 90 | 46a |
75-80% yield.