CHROMATOGRAPHIC AND MASS-SPECTROMETRIC STUDIES OF CYCLIC 2-(N,N-DIMETHYLAMINOMETHYL)FERROCENEBORONATES AND RELATED ESTERS

Cyclic 2-(N,N-dimethylaminomethyl)ferroceneboronate (DMAM-FcB) esters of a variety of 1,2-diols have been examined by gas and liquid chromat ography as well as by mass spectrometry. Some comparisons have been ma de with analogous ferroceneboronate (FcB) esters. Under the conditions used for reversed-phase high-performance liquid chromatography, more of the FcB than of the DMAM-FcB esters were stable. Many of the deriva tives were suitable for gas chromatography; the retention index increm ents for the dimethylaminomethyl substituent were on the order of 200 units on a methylsilicone phase. A satisfactory separation of diastere omeric boronates derived from chiral diols could be performed in the s ame achiral stationary phase. In most instances, the mass spectra of D MAM-FcB esters showed clear molecular ions along with prominent ions o f m/z (M-44), resulting from a loss of the (CH3)(2)N radical. Evidence for the formation of mono- and bis-boronates of ecdysterone was obtai ned by fast atom bombardment mass spectrometry.