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