Use of thiazoles in the halogen dance reaction: application to the total synthesis of WS75624 B.

The total synthesis of the pyridine-thiazole-containing natural product WS75624 B (1) is described. This synthesis proceeds via the Stille coupling of appropriately functionalized pyridine and thiazole components, and this paper details our studies on the use of the halogen dance reaction to prepare the desired thiazole. Various halogen dance reactions on thizoles are described, including a novel one-pot multistep reaction in which 2-bromothiazole is treated with LDA in the presence of a silyl chloride at -78 degrees C and quenched with an electrophile to provide the highly functionalized thiazole derivatives 27.