Total Synthesis of Prostaglandin F2.ALPHA. Using Nickel-Catalyzed Stereoselective Cyclization of 1,3-Diene and Tethered Aldehyde via Transmetalation of Nickelacycle with Diisobutylaluminum Acetylacetonate.
作者:Yoshihiro SATO、Masanori TAKIMOTO、Miwako MORI
DOI:10.1248/cpb.48.1753
日期:——
Total synthesis of prostaglandin F2alpha utilizing a nickel(0)-catalyzed cyclization of 1,3-diene and tethered aldehyde was achieved. The cyclization proceeded via a transmetalation of nickelacycle with diisobutylaluminum acetylacetonate (iBu2-ALAC). Thus, the reaction of 19, having a side chain corresponding to the alpha-chain in PGF2alpha with Ni(cod)2 (10 mol %), PPh3 (20 mol %), and 1,3-cyclohexadiene
利用镍(0)催化的1,3-二烯和束缚醛的环化反应,实现了前列腺素F2alpha的全合成。环化反应是通过镍环与二异丁基乙酰丙酮铝(iBu2-ALAC)的金属转移进行的。因此,具有对应于PGF2α中的α-链的侧链的19与Ni(cod)2(10mol%),PPh 3(20mol%)和1,3-环己二烯(25mol%)反应。 iBu2-ALAC(1.5当量)的存在进行立体选择,以54%的收率得到环化产物26。在19的环化过程中,侧链C-5处的Z-烯烃完全保留了其几何形状,并且立体选择性地构建了PGF2alpha中的四个连续的手性碳中心。成功实现了关键中间体19到PGF2alpha的转化。