White J D, Kranemann C L, Kuntiyong P
Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, USA.
Org Lett. 2001 Dec 13;3(25):4003-6. doi: 10.1021/ol010193a.
[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, and the composite 25 was subjected to a second palladium(II) acetate mediated methoxy carbonylation to yield 26, accompanied by acetoxy ester 27.
[反应：见正文] 由2-甲基恶唑-4-甲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，其中四氢吡喃周围的所有五个立体中心与佛波唑A的C环中的立体中心相对应。由13衍生得到的醛15通过维蒂希偶联与羟基烯烃23相连，复合物25在乙酸钯(II)的介导下进行第二次甲氧基羰基化反应，生成26，并伴有乙酰氧基酯27。
