Intramolecular Palladium(II)-Mediated Alkoxy Carbonylation as a Route to Functionalized Tetrahydropyrans. Synthesis of the C9−C32 Segment of Phorboxazole A
作者:James D. White、Christian L. Kranemann、Punlop Kuntiyong
DOI:10.1021/ol010193a
日期:2001.12.1
[reaction: see text] Hydroxy alkene 12, synthesized stereoselectively from 2-methyloxazole-4-carboxaldehyde, underwent intramolecular methoxy carbonylation in the presence of palladium(II) acetate to give 13 in which all five stereogenic centers around the tetrahydropyran correspond to those in ring C of phorboxazole A. Aldehyde 15, derived from 13, was linked to hydroxy alkene 23 via a Wittig coupling
[反应:见正文]由2-甲基恶唑-4-羧醛立体选择性合成的羟基烯烃12,在乙酸钯(II)存在下进行分子内甲氧基羰基化反应,得到13个,其中围绕四氢吡喃的所有五个立体中心均对应于将由13衍生的佛波唑A.醛的C环通过Wittig偶联与羟基烯烃23连接,然后对复合物25进行第二次乙酸钯(II)介导的甲氧基羰基化反应,生成26酯,并伴随乙酰氧基酯27 。