Expedient Synthesis of Furo[2,3-d][1,3]thiazinamines and Pyrano[2,3-d][1,3]thiazinamines from Enones and Thiourea.

Michael addition of thiourea to enones with subsequent intramolecular aminal ether formation provided easy access to furo[2,3-d]thiazinamines and pyrano[2,3-d][1,3]thiazin-2-amines. These amines served as versatile intermediates to a variety of beta-amyloid cleaving enzyme-1 (BACE1) inhibitors.