Heretofore, as a method of producing {HEAD ~ an estrone} acetal from androstane 1,4 diene 3,17 dione 17 acetal , there is, for instance, {TAIL ~ a method} as described in Japanese Patent Application Laid Open 
Heretofore , as a method of producing { HEAD ~ an estrone } acetal from androstane 1,4 diene 3,17 dione 17 acetal , there is , for instance , { TAIL ~ a method } as described in Japanese Patent Application Laid Open
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH