Toward a total synthesis of stigmatellin; an unproductive C-1 '-C-2 ' disconnection

Although the lithio derivative of the dimethylchromone 6c could be condense d with reactive organic electrophilic species and iodine to give, respectiv ely, homologated at C-1' (stigmatellin numeration) chromones and the iodide 6a, it proved impossible to convert efficiently either 6a or 6c into stigm atellin la by an anionic alkylation process. (C) 2000 Elsevier Science Ltd. All rights reserved.