作者:Jürg Gutzwiller、Werner Meier、Andor Fürst
DOI:10.1002/hlca.19770600717
日期:1977.11.2
Total Synthesis of (+)‐D‐Homoestrone 3‐methyl etherA novel total synthesis of (+)‐D‐homoestrone 3‐methyl ether (21) is described starting from (S)‐8a‐methyl‐3,4,8,8a‐tetrahydro‐2H, 7H‐naphthalene‐1,6‐dione (1) as a chiral synthon for the rings C and D. The key step involves alkylation of the derived 3 with m‐methoxyphenacyl bromide (4) as an AB‐building block to give the dioxo‐secosteroid 5. Hydrogenation of 5 affords the trans‐decalone 11. As by‐products the epimeric cis‐decalones 12 and 13 were characterized. Cyclization of 11 leads under kinetic control predominantly to the Δ9(11)‐tetraene 14. Catalytic hydrogenation of 14 and subsequent modification in ring D give the title compound 21. It was found that 14 and also the derived Δ8‐isomer 15a add hydrogen from the α‐face of the molecule to an extent of about 80%. The 8α‐D‐homoestrone derivatives 20a and 23 as well as the 9β‐isomers 19a and 22 were characterized.