A formal [3+3]-annulation-based approach to pancratistatins: total synthesis of (±)-7-deoxy-pancratistatinand its 2-epi and 2,4-diepi analogues

A full account is given for the total synthesis and the cytotoxic activity against the human lung tumoral cell line NCI-H460 of (+/-)-7-deoxy-pancratistatin and its 2-epi- and 2,4-diepi- unnatural analogues.