Studies Directed toward the Synthesis of Phomenoic Acid. Part 1. Enantioselective synthesis of the C(1)‐to‐C(6) segment

Abstract Based on a retrosynthetic analysis, a concept for the synthesis of all stereoisomers of the C(1)‐to‐C(6) segment of phomenoic acid has been developed. Both enantiomers of the chiral synthon 9 were prepared starting from rac ‐epoxy‐diester 10 . They were converted to both enantiomers of the epoxyalcohol, 16 and 21 , respectively, using Sharpless epoxydation. They served as building blocks for the synthesis of the tetrol derivatives 20 and 22 , respectively. All four stereoisomers were obtained in optically pure form. They contain the correct assembly of protected functional groups, allowing selective deprotection in view of further transformations.