Total Synthesis of Two Possible Diastereomers of Natural 6-Chlorotetrahydrofuran Acetogenin and Its Stereostructural Elucidation.

The first total synthesis of two possible diastereomers of natural 6-chlorotetrahydrofuran acetogenin 1 has been achieved. The synthetic route features 5-exo-tet cyclization, Z selective Wittig reaction and Julia olefination for the construction of conjugated diene and enyne moieties, and stereoselective chlorination. Comparison of their H and C NMR data and specific rotation with those of the natural product elucidated the absolute configuration of natural (-)-6-chlorotetrahydrofuran acetogenin 1.