Stereochemistry of sagittamide A: prediction and confirmation.

[structure: see text] The C5-C10 relative stereochemistry of sagittamide A was predicted, with the use of the 3JH,H profiles assembled from the spin-coupling constants reported in the literature. The predicted relative stereochemistry was then confirmed by a total synthesis of two relevant remote diastereomers. The absolute configuration of sagittamide A was established through a detailed 1H NMR analysis of the two remote diastereomers, followed by doping experiments of them with the authentic natural product.