Amberg Matthias, Bergsträsser Uwe, Stapf Georg, Hartung Jens
Fachbereich Chemie, Technische Universität Kaiserslautern, Kaiserslautern, Germany.
J Org Chem. 2008 May 16;73(10):3907-10. doi: 10.1021/jo7026068. Epub 2008 Apr 15.
2-Chloro-(4 R,5 R)-bis[(1 R,2 S,5 R)-menth-1-yloxycarbonyl)]-1,3,2-dioxaphospholane is a practical reagent for reliably determining enantiomeric purity of chiral alcohols via (31)P NMR spectroscopy. The compound is available as a crystalline solid on a 20 g scale from PCl 3 and bis[(1 R,2 S,5 R)-menth-1-yl] tartrate. It is comparatively inert toward spontaneous hydrolysis under conventional laboratory conditions but undergoes quantitative substitution of alkoxide for chloride if treated with a chiral alcohol. Nonequivalent (31)P NMR signals of diastereomeric 2-alkoxy-1,3,2-dioxophospholanes were dispersed by approximately 1.4-0.1 ppm. The associated integral ratios reflected enantiomeric purities of preweighted samples of ( R)- and ( S)-1-phenylethanol, (+)- and (-)-menthol, and a set of primary, secondary, and tertiary alcohols with a precision of +/-0.4-1.0%.
2-氯-(4R,5R)-双[(1R,2S,5R)-薄荷-1-基氧基羰基]-1,3,2-二氧磷杂环戊烷是一种实用试剂，可通过³¹P核磁共振光谱法可靠地测定手性醇的对映体纯度。该化合物可由三氯化磷和双[(1R,2S,5R)-薄荷-1-基]酒石酸酯以20克规模制备成结晶固体。在常规实验室条件下，它对自发水解相对惰性，但如果用手性醇处理，会发生醇盐对氯的定量取代。非对映体2-烷氧基-1,3,2-二氧磷杂环戊烷的不等价³¹P核磁共振信号分散约1.4 - 0.1 ppm。相关的积分比反映了预先称重的(R)-和(S)-1-苯乙醇、(+)-和(-)-薄荷醇以及一组伯醇、仲醇和叔醇样品的对映体纯度，精度为±0.4 - 1.0%。
