Table 1. Aldol addition of diketone 4 via pathways a and b.
entry | reagent ia | isolated yield (%) | |||
---|---|---|---|---|---|
8 | 9 | 10 | 11 | ||
1 | TFA | 45 | 0 | 40 | 0 |
2 | NaH | 56 | 0 | 6 | 0 |
3 | Pyrrolidine | 80 | 0 | 8 | 0 |
4 | LDA | 71 | 0 | 22 | 0 |
5 | LiHMDS | 65 | 0 | 25 | 0 |
6 | LiTMP | 48 | 0 | 43 | 0 |
7 | Ph3CLi | 79 | 0 | 5 | 0 |
8 | Al2O3 | 81 | 7 | 0 | 0 |
9 | TiCl4 | 50 | 0 | 32 | 0 |
See Experimental Section for detailed experimental procedures