An easy, four-step route to (+/-)-erythro-2-dodecyl-3-methylbutanedioic aci
d (roccellic acid, 9) with 60% overall yield has been described. Wittig rea
ction of the citraconimide-TPP adduct with dodecanal furnished the mixture
of (E)- and (Z)-isomers 3 and 4, which, on base-catalysed exocyclic to endo
cyclic double bond isomerisation, yielded maleimide 5. Catalytic cis-hydrog
enation of 5 using Adam's platinum dioxide catalyst followed by acid-cataly
sed hydrolysis of formed succinimide 8 gave desired (+/-)-erythro-roccellic
acid 9.