Total synthesis of Biotin (Fujisawa):
| Reference: | Fujisawa, T.; Nagai, M.; Koike, Y.; Shimizu, M. J. Org. Chem. 1994, 59, 5865. DOI |
| Reactions: | Li-Alkynyl+Aldehyde • Li/H → Li-Alkynyl • Hydrogenation EneSulfide • Felkin-Anh Chelation • N-H → N-Alkyl (2°) • Alkyne Hydrosulfidation • Sulfide-5 • N-H → N-C(O)NR2 • N-Boc → N-H • O-H → O-SO2Ar • |
| Reagents: | Alkynyl-ZnX • TsOH • Isocyanate • KH • TsOH • Hydroxide, cesium • H2, Pd • HBr • Microbial oxidation • |