Synthese von Phosphono�pfels�ureestern durch Reduktion von 3-Phosphonopyruvaten
摘要:
The reduction of 3-phosphonopyruvates with ammonia-borane complex proceeds with a very high diastereoselectivity (25:1). Syn- and anti-diastereoisomeric hydroxy esters could be unambiguously assigned by NMR spectroscopy. Furthermore, other beta-ketophosphonates could easily be reduced. Thus, diethyl-3,3-diethoxy-2-hydroxybutyl phosphonate was obtained which gave diethy-2-hydroxy-3-oxobutyl phosphonate after hydrolysis the first known phosphonoacyloine.
reaction with 4-(ethoxycarbonyl)-3-ethyl-2-(2-nitroethyl)pyrrole, and subsequent reductive cyclization provided the spiro-piperidine-1-methyldihydrodipyrrin. Treatment with SeO2 followed by trimethyl orthoformate under acid catalysis converted the 1-methyl group to a 1-(1,1-dimethoxymethyl) motif. Self-condensation of the resulting spiro-piperidine-dihydrodipyrrin-acetal afforded the 5-methoxy- or 5-unsubstituted
Synthese von Phosphono�pfels�ureestern durch Reduktion von 3-Phosphonopyruvaten
作者:R. Neidlein、H. Feistauer
DOI:10.1007/bf00807637
日期:1997.1
The reduction of 3-phosphonopyruvates with ammonia-borane complex proceeds with a very high diastereoselectivity (25:1). Syn- and anti-diastereoisomeric hydroxy esters could be unambiguously assigned by NMR spectroscopy. Furthermore, other beta-ketophosphonates could easily be reduced. Thus, diethyl-3,3-diethoxy-2-hydroxybutyl phosphonate was obtained which gave diethy-2-hydroxy-3-oxobutyl phosphonate after hydrolysis the first known phosphonoacyloine.