The stereocontrolled total synthesis of altohyrtin A/spongistatin 1: the CD-spiroacetal segment
作者:Ian Paterson、Mark J. Coster、David Y.-K. Chen、Karl R. Gibson、Debra J. Wallace
DOI:10.1039/b504148a
日期:——
Stereocontrolled syntheses of the C16-C28 CD-spiroacetal subunit of altohyrtin A/spongistatin1 , relying on kinetic and thermodynamic control of the spiroacetal formation, are described. The kinetic control approach resulted in a slight preference (60 : 40) for the desired spiroacetal isomer. The thermodynamic approach allowed ready access to the desired spiroacetal by acid-promoted equilibration
依赖于螺缩醛形成的动力学和热力学控制,描述了altohyrtin A /海绵抑素1的C16-C28 CD-螺缩醛亚基的立体控制合成。动力学控制方法导致所希望的螺缩醛异构体稍微偏爱(60∶40)。通过热力学方法,可以通过酸促进的平衡,C23差向异构体的色谱分离以及不希望的异构体重新达到平衡条件,从而容易地获得所需的螺缩醛。这种可扩展的合成序列提供了数克的,因此能够成功完成altohyrtin A /海绵体抑素1的总合成,如本系列文章的第4部分所报道。
A Practical and Efficient Synthesis of the C-16−C-28 Spiroketal Fragment (CD) of the Spongistatins
作者:Matthew J. Gaunt、David F. Hook、Huw R. Tanner、Steven V. Ley
DOI:10.1021/ol035848h
日期:2003.12.1
A practical and efficient route to the CDspiroketal (C-16-C-28) of the spongistatins is reported. Two stereocenters are introduced from chiral building blocks with the remainder introduced by substrate-controlled transformations. The key beta-keto-1,3-dithiane intermediate is generated by a dithiol conjugate addition to an ynone and the 1,3-dithiane unit in the C-ring plays a key role in the spiroketalization