Total synthesis of sphingofungin F by orthoamide-type overman rearrangement of an unsaturated ester

Org Lett. 2015 Apr 3;17(7):1704-7. doi: 10.1021/acs.orglett.5b00475. Epub 2015 Mar 13.

Abstract

The total synthesis of sphingofungin F through the Overman rearrangement of an unsaturated ester, which is known to be an unsuitable substrate under standard conditions due to the competitive aza-Michael reaction, is described. The developed conditions enabled the ester to be compatible with the original Overman rearrangement, providing quick access to α,α-disubstituted amino acids by minimizing extra protecting group manipulations and redox reactions.