Synthesis of 2,3-Anti-3,4-anti and 2,3-Anti-3,4-syn Propionate Motifs: A Diastereoselective Tandem Sequence of Mukaiyama and Free-Radical-Based Hydrogen Transfer Reactions
作者:Yvan Guindon、Michel Prévost、Philippe Mochirian、Brigitte Guérin
DOI:10.1021/ol025605+
日期:2002.3.1
[reaction: see text] Reported herein is a strategy employing a Mukaiyama reaction in tandem with a hydrogen transfer reaction for the elaboration of 2,3-anti-3,4-anti and 2,3-anti-3,4-syn propionate motifs. The mode of complexation is controlled through monodentate or chelate pathways for the Mukaiyama reaction to give access to either syn or anti aldol products, precursors of the free-radical reduction
[反应:见正文]本文报道的是将Mukaiyama反应与氢转移反应串联使用的策略,用于合成2,3-抗-3,4-抗和2,3-抗-3,4-辛酸丙酸酯图案。通过Mukaiyama反应的单齿或螯合途径来控制络合方式,从而可以得到顺式或反式羟醛产物(自由基还原反应的前体)。路易斯酸硼用于通过环外途径控制自由基反应。
Preparation of (2E,4E,6S,7S,10E,12E,14S,15S,1′S)-7,15-Bis(1′-hydroxymethylethyl)-6,14-dimethyl-8,16-dioxa-2,4,10,12-cyclohexadecatetraene-1,9-dione. – A Building Block for the Synthesis of Elaiophylin
作者:Richard F. W. Jackson、Marius A. Sutter、Dieter Seebach
DOI:10.1002/jlac.198519851203
日期:1985.12.22
The title compound 2, which is considered to be a possible key intermediate for a synthesis of the antibiotic elaiophylin (1), has been obtained by cyclodimerisation of the hydroxy acids 18 and 27 using Yamaguchi's method. The hydroxy acids 18 and 27 are synthesised by Wittig reaction of the (phosphoranylidene)crotonate 14 with the protected 3,5-dihydroxy-2,4-dimethylpentanals 12 and 23, respectively
使用山口氏方法通过羟基酸18和27的环二聚反应,获得了标题化合物2,该标题化合物2被认为是合成抗生素鞣花素(1)的可能的关键中间体。所述羟基酸18和27是由合成的Wittig的(膦基亚基)巴豆反应14与受保护的3,5-二羟基-2,4- dimethylpentanals 12和23,分别。这些反过来是由之间的非对映选择性Evans aldol反应(p)-3-苄氧基-2-甲基丙醛(4)和(R)-4-异丙基-3-丙酰基-2-恶唑烷二烯。