NaH promoted [4+3] annulation of crotonate-derived sulfur ylides with thioaurones: synthesis of 2,5-dihydrobenzo[4,5]thieno[3,2-b]oxepines.

NaH promoted [4+3] annulation of crotonate-derived sulfur ylides with thioaurones: synthesis of 2,5-dihydrobenzo[4,5]thieno[3,2-b]oxepines.