作者:H. T. Nagasawa、D. J. W. Goon、F. N. Shirota
DOI:10.1002/jhet.5570180538
日期:1981.8
boxylic acid (1a), with a 3.3 to 1 predominance of the 2S (cis) isomer, was shown to epimerize at the C-2 position in neutral, protic solvents. This was manifested by mutarotation concomitant to changes in the ratios of the C-4 methine proton resonances in the nmr spectrum. Compound 1a was stable in dilute sodium carbonate solution, but underwent rapid equilibration in 1N hydrochloric acid.
2(R,S)-5,5-Trimethylthiazolidine-4-(S)-羧酸(1a)具有2:3(顺式)异构体的3.3比1的优势,在图2中的C-2位置有差向异构。中性质子溶剂。这通过伴随旋转的nrr谱图中的C-4次甲基质子共振比的变化来证明。化合物1a在稀碳酸钠溶液中稳定,但在1 N盐酸中迅速平衡。