A Practical Synthesis of Highly Functionalized Fused 1,6-Dihydroimidazo-[1,2-a]imidazole-2,5-diones, Key Intermediates for LFA-1 Inhibitors

In Scheme 1 the structure of compound 7was incorrectly shown. The correct Scheme 1 is:

In Scheme 4, compound 9was incorrectly represented. The correct Scheme 4 is:

The authors and the editorial office apologize for these mistakes.