Synthesis and some spectral characteristics of bicyclic phosphate, GABA antagonists.

Abstract

Bicyclic phosphates (BPs), GABA antagonists, were prepared by reaction of the corresponding triols with phosphoryl chloride. The triols were obtained by one of the following methods: (a) the Tollens condensation of an aldehyde possessing α-hydrogen atoms with formaldehyde; (b) the base-catalyzed hydroxymethylation of alkylmalonates or α-alkylacetoacetates with paraformaldehyde, followed by reduction; (c) the reduction of diethyl pivaloylmalonate; or (d) the halogenation of pentaerythritol. Some BPs were also derived by modification of the functional groups of BP homologs. The 1H-NMR spectra of 4-substituted BPs showed a characteristic doublet peak due to the endocyclic methylene protons, the shift position of which was affected by the electronic nature of the bridgehead substituent. The mass spectra of the PBs were characterized by peaks due to the loss of CH2O from the ring.