2-alkylcyclobutanones as markers for irradiated foodstuffs - I. Synthesis of saturated and unsaturated standards

The reaction scheme suggested for the synthesis of 2-alkylcyclobutanone standards, the key step being a Wittig reaction between a protected ketoaldehyde and phosphoranes with alkyl chains of variable length, has made it possible to prepare different 2-alkylcyclobutanones with saturated alkyl chains (C6 to C14) (in yields varying from 27 to 36%) as well as 2-alkylcyclobutanones with monounsaturated chains (C12 and C14) (in yields of 23 and 17%). In addition, the 2-alkylcyclobutananes synthesized with an odd number of carbon atoms in the saturated alkyl chain, especially 2-undecylcyclobutanone (C11), might be utilized as internal standards when assaying these chemical compounds by GC/MS. (C) 1999 Elsevier Science Ltd. All rights reserved.