A convergent synthesis of carbocyclic sinefungin and its C5 epimer.

A convergent synthesis of carbocyclic sinefungin 2 and its C5 epimer 3 is described. The key features in our synthesis include the use of commercial available L-methionine and readily available (1R, 4S)-4-hydroxy-2-cyclopentenyl acetate as starting materials, cross-metathesis coupling, enzymatic kinetic resolution and Staudinger reduction. The current synthesis is flexible and therefore provides convenient access to the synthesis of various carbocyclic SIN analogues for biological evaluation.