Total synthesis of natural products possessing α,α-disubstituted α-amino acid substructure

ORGN 268

Yasufumi Ohfune, ohfune@sci.osaka-cu.ac.jp, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Osaka, 558-8585, Japan
Natural products possessing an α,α-disubstituted α-amino acid substructure have received significant attention because of their structural complexity as well as potent biological activity. Many methods have been developed for the enantio- and diastereoselective synthesis of α,α-disubstituted α-amino acids, many of which are focused on the total synthesis of natural products and related bioactive compounds. In this presentation, we wish to describe our recent advances in the total synthesis of natural products such as manzacidin A~C, kaitocephalin, 5,6,11-trideoxytetrodotoxin, and amathaspyramide F which involve an amino group attached to a quarternary carbon center in their substructure. The key methods for asymmetric construction of these higher-order structures are accomplished using an asymmetric version of the Strecker synthesis of α-acyloxy ketones or the enolate-Claisen rearrangement of α-acyloxy allylsilanes where an α-amino acid was employed as an acyloxy group.