4-methoxy-3-oxo-1,3-dihydroisobenzofuran-3-13C-1-carbonitrile 、
(6S,8S)-6-(tert-Butyl-dimethyl-silanyloxy)-6-[(S)-1-(tert-butyl-dimethyl-silanyloxy)-ethyl]-4,4-dimethoxy-8-methoxymethoxy-5,6,7,8-tetrahydro-4H-naphthalen-1-one 以95%的产率得到rac-(8R,10R)-8-((tert-butyldimethylsilyl)oxy)-8-((R)-1-((tert-butyldimethylsilyl)oxy)ethyl)-11-hydroxy-1,6-dimethoxy-10-(methoxymethoxy)-7,8,9,10-tetrahydrotetracene-5,12-dione-12-13C