Synthesis of (+) and (‐)‐Streptomyces coelicolor Butanolide 5 (SCB‐5)

Abstract Various 1‐(1‐hydroxyalkyl) paraconyl alcohols are important signaling molecules within antibiotics production in Streptomyces sp. Intending developing a flexible convergent chemical synthesis of such butanolides, zwitterionic aza‐Claisen rearrangement was chosen as reliable strategy generating the central stereotriad. Reaction enantiopure N ‐allyl pyrrolidines and 4‐phenylbutenoic acid fluoride delivered defined configured amides displaying 2,3,1’ stereotriads. The configuration determined by allyl alcohol moiety indicating complete remote stereo control. Amide removal iodolactonization proceeding reductions, halocyclization elimination gave key alkylidene tetrahydrofuran derivatives. Stepwise degradation olefins through ozonolysis, reductive work‐up protecting group both enantiomers target coelicolor butanolide 5.