Synthesis of an Orthogonally Protected Polyhydroxylated Cyclopentene from l-Sorbose

The use of l‐sorbose in the synthesis of functionalized cyclopentene derivatives was accomplished. These cyclopentene derivatives are related to those found in naturally occurring jatrophane frameworks and in other bioactive compounds. The formation of allyl α‐l‐sorbopyranoside was a key synthetic step. Regioselective introduction of protecting groups was followed by the hydrolysis of the allyl glycoside to furnish a fully protected acyclic l‐sorbose derivative. This acyclic intermediate was subsequently used to give an orthogonally protected polyhydroxylated cyclopentene, which has potential for further synthesis of bioactive compounds. The protected cyclopentene itself showed a clear cytotoxic activity when tested against a panel of human cancer cell lines (HT29, LS174T, SW620, A549, and HeLa cells). Well protected: A new strategy for the orthogonal protection of the readily available natural sugar L‐sorbose has been developed. Using this approach, we prepared a cyclopentene derivative which is related to important biologically active natural products. This cyclopentene showed a clear cytotoxicity in several cancer cell lines (HT29, LS174T, SW620, A549, HeLa cells).