J. Degraw, P. H. Christie, T. Cairns
Aug 1, 1982
Citations
0
Influential Citations
4
Citations
Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
Alkylation of ethyl acetoacetate-13C4 with ethylene oxide and ethylene oxide-13C2 afforded 2-acetylbutyrolactone-13C4 (4a) and the hexalabeled form (4b), respectively. Treatment of the lactone with an excess of 48% hydrobromic acid effected decarboxylation with bromide displacement to yield 5-bromo-2-pentanone labeled with 3 or 5 carbon-13 atoms (5). The bromo ketone was converted to the ethylene ketal with ethylene glycol and p-toluenesulfonic acid catalysis. Displacement of the bromide by sodio diethyl phosphite gave the required ethylene ketals of 5-(diethylphosphono)-2-pentanone (7). A convenient process for preparation of ethylene-13C2 oxide from acetic-13C2 acid is also described.