Practical asymmetric synthesis of a novel γ-secretase inhibitor

An efficient route to γ-secretase inhibitor hydroxyl thiophene sulfonamide 1 is described. The approach contains nine steps with an overall yield of 8%. The synthesis highlights a diastereoselective methylation using Evansʹ oxazolidinone method and a chiral Strecker reaction via Davisʹ sulfonimine protocol.