Chiral symmetric phosphoric acid esters as sources of optically active organophosphorus compounds
摘要:
Chiral symmetric di- and trialkylphosphites, derivatives of (-)-borneol, (-)-menthol and (-)-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose, were studied as starting reagents for the preparation of chiral organophosphorus compounds. The reaction occurs by asymmetric induction at the alpha-carbon atom of substituted alpha-alkylphosphonates. The stereoselectivity of the reaction depends on the structure of the starting compounds and the reaction conditions. The configuration of the alkylphosphonates was established by NMR spectroscopy, by transformation into alpha-hydroxyalkylphosphonic acids and by X-ray crystal structure analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.
Enantioselective reduction of ketophosphonates using adducts of chiral natural acids with sodium borohydride
作者:E.V. Gryshkun、V. Nesterov、O. I. Kolodyazhnyi
DOI:10.3998/ark.5550190.0013.409
日期:——
asymmetric reduction of αand β ketophosphonates using chiral complexes prepared from sodiumborohydride and natural aminoacids or tartaric acids was developed. Reduction of α or β ketophosphonates by these reagents led to formation of chiral (S)or (R)hydroxyphosphonates. Reduction of chiral di-(1R,2S,5R)-menthylketophosphonates by the chiral complexes NaBH4/(R,R)-proline or NaBH4/(R,R)-tartaric acid due to