Phosphorylated cyclopropanes in the synthesis of α-alkylidene-γ-butyrolactones: total synthesis of (±)-savinin, (±)-gadain and (±)-peperomin E
作者:Matthew G. Lloyd、Richard J. K. Taylor、William P. Unsworth
DOI:10.1039/c6ob01527a
日期:——
Phosphorylated cyclopropanes, generated via the Rh(II)-catalysed intramolecular cyclopropanation of α-(diethoxyphosphoryl)acetates, have been found to be useful precursors in the synthesis of α-alkylidene-γ-butyrolactones. These cyclopropyl intermediates undergo regioselective reductive ring-opening and subsequent Horner–Wadsworth–Emmons olefination to complete the synthesis. Total syntheses of (±)-savinin
An efficient approach to the synthesis of enantiomerically pure trans-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids
作者:Katarzyna Wąsek、Jacek Kędzia、Henryk Krawczyk
DOI:10.1016/j.tetasy.2010.07.017
日期:2010.9
The synthesis of (1R,2S)- and (1S,2R)-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids was accomplished using different strategies. The (1R,2S)-stereoisomer could be efficiently obtained by the cyclopropanation of ethyl diethoxyphosphorylacetate with the cyclic sulfate derived from (S)-3-benzyloxy-1,2-propandiol as a key step. The (1S,2R)-stereoisomer was synthesized from a readily available (1S,5R)-3-oxabicyclo[3.1.0]hexan-2-on-1-phosphonate. (C) 2010 Elsevier Ltd. All rights reserved.