2,3-Bisphosphonosuccinic Acid Hexamethyl Ester [(CH₃O)₂(O)P-CH-COOCH₃]₂ – NMR-Spectroscopic Studies of ABX and [AM₃R₃X]₂+Z₆ Spin Systems

GRAPHICAL ABSTRACT

Abstract

Addition of dimethyl phosphite to the triple bond of dimethylacetylene-dicarboxylate by conventional routes or assisted by microwaves leads predominantly to the meso form of 2,3-bisphosphonosuccinic acid hexamethyl ester [(CH₃O)₂(O)P-CH-COOCH₃]₂. Molecular structure and dominant rotamer were deduced from multinuclear ³¹P{¹H}-, ¹³C{¹H}-, ¹H-, ¹H{³¹P}-NMR studies on ABX and [AM₃R₃X]₂+Z₆ spin systems. Vicinal coupling constants ³J_PP, ³J_PH, and ³J_HH were used as stereochemically relevant parameters to deduce rotamer preferences via Karplus-type relationships.

Keywords:

• Meso 1, 2-ethane-bisphosphonate
• 2,3-bisphosphonosuccinate
• ³¹P{¹H}
• ¹³C{¹H}
• ¹H
• ¹H{³¹P}
• spectral analysis
• ABX, [AM₃R₃X]₂+Z₆
• ³J_PP

Additional information

Funding

Stefan Jankowski and Krzysztof Huben received support from Łodz University of Technology (Grant DS-I18/10/2013). György Keglevich is grateful for the support from the Hungarian Scientific Research Fund (OTKA K83118).