Asymmetric Synthesis of the Tetrahydropyran Ring, C32−C38 Fragment, of Phorboxazoles
作者:Yasmin Brinkmann、M. Carmen Carreño、Antonio Urbano、Françoise Colobert、Guy Solladié
DOI:10.1021/ol048099s
日期:2004.11.1
of phorboxazoles, (2R,4R,6R)-1, is described using a sulfoxide as chiral auxiliary. Key advances include the stereoselective reductions of beta-keto- or beta,gamma-diketosulfoxides, the acid-catalyzed cyclization of enantiopure sulfinyl hydroxy ketone precursors to the tetrahydropyran ring, and the Pummerer reaction on the pendant sulfoxide to create the formyl group.
使用亚砜作为手性助剂描述了模型醛(2R,6R)-2和佛波唑的C32-C38片段(2R,4R,6R)-1的不对称合成。关键的进展包括立体选择性地还原β-酮或β,γ-二酮亚砜,对映体纯的亚磺酰基羟基酮前体到四氢吡喃环的酸催化环化以及亚砜侧基上的Pummerer反应产生甲酰基。