3-(tert-butyldimethylsilyloxy)-1-methoxy-1-trimethylsilyloxybuta-1,3-diene 、
toluene-4-sulfonic acid 7-chloro-2-methyl-4,6,9-trioxo-6,9-dihydro-4H-benzo[g]chromen-5-yl ester 以
苯 为溶剂,
反应 4.0h,
以45%的产率得到toluene-4-sulfonic acid 9-(tert-butyldimethylsilyloxy)-7-hydroxy-2-methyl-4,6,11-trioxo-6,11-dihydro-4H-1-oxanaphthacen-5-yl ester