A Concise and Highly Efficient Synthesis of Trehazolin and Trehalamine Starting from d -Mannose

A concise synthesis of trehazolin, its aglycon, trehalamine, and a known analogue has been developed starting from d -mannose. This new approach features a very stereoselective and high-yielding ketone−oxime ether reductive carbocyclization promoted by samarium diiodide as a key step for the preparation of the aminocyclitol component and a mild and very efficient intramolecular triflate displacement reaction for the construction of the oxazoline ring.