Enantioselective Catalytic [4+1]‐Cyclization of ortho ‐Hydroxy‐ para ‐Quinone Methides with Allenoates

The first highly asymmetric catalytic synthesis of densely functionalized dihydrobenzofurans is reported, which starts from ortho ‐hydroxy‐containing para ‐quinone methides. The reaction relies on an unprecedented formal [4+1]‐annulation of these quinone methides with allenoates in the presence of a commercially available chiral phosphine catalyst. The chiral dihydrobenzofurans were obtained as single diastereomers in yields up to 90 % and with enantiomeric ratios up to 95:5.