A total synthesis of PF1163B has been achieved. The vinylogous Mukaiyama aldol reaction of ketene silyl N, O -acetal 6 (ent - 6) mediated by excess TiCl 4 proceeded with saturated aldehydes to give adduct 10 in moderate yield with moderate stereoselectivity. The major isomer is the diastereomer that was provided by using one equivalent of TiCl 4 . The Birch reduction of α,β-unsaturated imide 4, possessing a less hindered side chain, gave 12 in good stereoselectivity by employing 2-isopropylbenzimidazole as a bulky proton source. After elongation of the carbon chain and connection with the amino acid part, we accomplished a total synthesis of PF1163B. These methods constitute a concise synthetic route to obtain polyketides as well as depsipeptides.
ASJC Scopus subject areas
- Organic Chemistry