Sequential Organocatalyzed Michael Addition/[3 + 2]-Heterocyclization for the Stereoselective Synthesis of Fused-Isoxazoline Precursors of Enantiopure Cyclopentanoids
摘要:
We propose an asymmetric synthesis of functionalized cyclopentanoids bearing up to four stereogenic centers from easily accessible nitroalkenes and unsaturated aldehydes. The overall sequence includes an enantioselective organocatalytic Michael addition and a [3 + 2]-heterocyclization between an in situ generated silyInitronate and the unactivated double bond. Finally, the fused isoxazoline can be further transformed to various cyclopentanoids.