✍ Scribed by R.Alan Aitken; Nazira Karodia
No coin nor oath required. For personal study only.
The simple phosphonium salts 4 and 5 have been fully characterised for the first time and are found by NMR spectroscopy to exist in CDC13 solution mainly as the E and Z enol structures b and c. The salt 6 exists as a mixture of the keto form a and one enol form assumed to be b. Similarly the bis(phosphonium salt) 16 exists entirely with one end in the keto form and the other in the enol form. The ylide/phosphonium salt 17 obtained from 16 by treatment with base also exists as an enol which is resistant to further deprotonation. Fully assigned 13C NMR spectra are presented for all the structures involved.
📜 SIMILAR VOLUMES
Complete analyses of the proton and carbon chemical-shift assignments of D-mannurono-y-lactone (1) have been achieved by 1D and 2D NMR spectral measurements. At equilibrium, the anomeric LY and p forms were present in the ratio of 34:66 in D,O and 72:28 in Me,SO-d,. The solution data indicated tha