Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Addition of lithiated methoxyallene 2 to optically active N-benzyl-Boc-protected amino aldehydes 12-14 and to aldehyde 16 provides products 17-20 with good to excellent diastereoselectivity. These adducts are subsequently cleaved by ozonolysis to give α-hydroxy-β-amino acid derivatives 21-25 in good overall yield. By conversion into an oxazolidone derivative, the configuration of the major diastereomer was determined to be anti (2S,3S). Thus, the additions of 2 follow the course proposed by the Felkin-Anh model and are not ruled by chelation effects. The diastereoselective synthesis of 22 constitutes one of the simplest routes to a protected norstatine derivative.
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