31 環上での立体制御反応を利用した16員環マクロリド類の合成(口頭発表の部)  [in Japanese] 31 Stereoselective Total Synthesis of 16-Membered Macrolide Aglycons via Stereoselective Epoxidation and Reduction Based on the Conformational Control of Macrolide Rings  [in Japanese]

The 16-membered aglycones of the largest group of macrolide antibiotics are classified into four types I, II, III and IV, according to their oxidation level. The stereoselective synthesis of I-IV by reduction and/or epoxidation on the basis of the conformational control of 16-membered rings were described. The C1-C10 (1) and C11-C15 segment (2) were coupled and cyclized by the intramolecular Wittig-Horner reaction to give a 16-membered lactone (4), which was converted to ten typical macrolide aglycones(Ia-IVc). Conformation of each-compound was controlled by changing the protection pattern of 3,5,6"-hydroxy groups. The complete stereoselective reduction and epoxidation were achieved, and the results of the diastereoselectivity of C9 carbonyl reduction and the epoxidation were clearly explained by coupled with NOE, NOESY measurement, X-ray analysis and MMP2-CONFLEX2 calculation.