M. Pomerantz, R. Fink
1979
Citations
0
Influential Citations
6
Citations
Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
The synthesis of the triply 13C labeled molecule, diethyl 1-[(13C)methyl]-3-Phenyl(1,3-13C2)bicyclo[1.1.0]butane-exo,exo-2,4-dicarboxylate is described. The unique feature of the synthesis is that in three instances we employed 13CO2 (from Ba13CO3) without using a high vacuum line. We found that excellent yields were obtained in two Grignard reagent carbonations and in a CO2 reduction using a mechanical pump which produced a vacuum of 0.05 torr. The synthetic sequence involved carbonation of phenylmagnesium bromide to give (α-13C)benzoic acid, reduction with LiAlH4, conversion to the corresponding benzyl chloride followed by preparation of the Grignard reagent and carbonation to produce phenyl (1,2,-13C2)acetic acid. Reaction with 13CH3Li provided 1-Phenyl-2-(1,2,3-13C3)-propanone which, after conversion to its hydrazone and reaction with mercurous trifluoroacetate, yielded 1-phenyl-1-(1,2,3-13C3)propyne. Reaction twice with carboethoxycarbene (from ethyl diazoacetate) gave the desired triply 13C labeled bicyclobutane.