Table 1.
Enantioselective synthesis of six well-known indole alkaloid
 | ||||
|---|---|---|---|---|
| Compound | No. steps here* |
Overall yield (%) |
PSAC steps |
PSCA steps |
 |
12 | 6.4 | 25 (refs 19,20) | 16 (ref. 21) |
 |
9 | 24 | 13 (ref. 30) | 11 (ref. 29) |
 |
9 | 14 | NA | 19 (ref. 32) |
 |
10 | 10 | NA | NA |
 |
11 | 8.9 | NA | 10 (ref. 31) |
 |
11 | 10 | NA | NA |
Step counts represent the longest linear sequence from commercially available 9. NA, not applicable. PSAC, previous shortest asymmetric catalytic synthesis; PSCA, previous shortest chiral auxiliary or chiral pool synthesis.
*
See Supplementary Information for details of these syntheses.