Synthetic application of acylnitroso Diels-Alder derived aminocyclopentenols: total synthesis of (+)-streptazolin.

Concise total syntheses of (+)-streptazolin 1 and its more stable dihydro derivative 2 were accomplished via an intramolecular aldol condensation strategy starting from readily available aminocyclopentenol (-)-7. The synthetic sequence included reductive amination, stereoselective epoxidation, intramolecular aldol (and condensation) reaction, and Wittig reaction. The overall yield for dihydro derivative 2 from aminocyclopentenol (-)-7 was about 7% for a total of 14 steps.