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