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.