2,12-dihydroxy-7,7-dimethyl-10-oxapentacyclo[11.8.0.03,11.04,9.015,20]henicosa-1(13),2,4(9),11,15,17,19-heptaene-5,14,21-trione 、
乙酸酐 在
吡啶 作用下,
反应 24.0h,
以57%的产率得到(12-acetyloxy-7,7-dimethyl-5,14,21-trioxo-10-oxapentacyclo[11.8.0.03,11.04,9.015,20]henicosa-1,3(11),4(9),12,15,17,19-heptaen-2-yl) acetate