Synthesis of the Apratoxin 2,4-Disubstituted Thiazoline via an Intramolecular Aza-Wittig Reaction

[reaction: see text] In developing a synthetic entry to the thiazoline-containing domain of the apratoxin natural products, we converted vicinal azido-thiolesters into 2,4-disubstituted thiazolines via sequential one-pot Staudinger reduction/aza-Wittig reaction. This method of de novo thiazoline formation provides a mild and versatile process that is particularly well suited to acid-sensitive substrates.