Stereocontrol by quaternary centres: a stereoselective synthesis of (?)-luminacin D

Very high diastereoselectivity can be achieved by 1,3-chelation-controlled allylation of aldehydes that possess a non-chelating ?-ether substituent, even if the ?-position is a quaternary centre and/or a spiro-epoxide. This reaction was used as a key step in an enantioselective synthesis of the angiogenesis inhibitor luminacin?