Part 1 我們發展出了一種新的氫化方式用來還原鹵烯類化合物。利用Cu(II)/Fe(III)的複合物和hydrazine，可以選擇性的氫化具有類固醇結構的鹵烯類化合物，而有效的合成出17b halo-的類固醇化合物。此類化合物有可能是抗雌激素或是雌激素受體的顯像劑。而此化反應具有高的b立體選擇性且沒有副產物的產生。 Part 2 我們發展出一種新的合成方法來合成含硫烷類或芳香族鏈鍵劑的CMP-Neu5Ac衍生物。此合成方式包含了將peracetylated sialic acid methyl ester和mercaptoalkyl (aryl) trichloroacetate連接在一起，且具有很高的b-立體選擇性。接著可以選擇性的將trichloroacetyl group去掉，而得到hydroxyalkyl及hydroxyaryl thioglycosides。最後經由O-phosphitylation、氧化及去保護的步驟可得到最終產物。 Part 1 A new system for hydrogenation of haloalkenes is reported. Cu(II)/Fe(III)-mediated selective hydrogenation of steroidal haloalkenes in the presence of hydrazine proves to be a very efficient method for the synthesis of 17b-halosteroids, potential candidates as antiestrogens or androgen receptor-mediated imaging agents. The reaction stereo- specifically affords b-haloalkanes without any concomitant formation of dehalogenation products. Part 2 A new approach to the synthesis of anomeric sulfur analogues of CMP-Neu5Ac containing alkane or arene linkage is described. The procedure involves the high b-stereoselectivity in sialylation of the peracetylated sialic acid methyl ester with mercaptoalkyl (aryl) trichloroacetate, followed by selective deprotection of the trichloroacetyl group to the corresponding hydroxyalkyl and hydroxyaryl thioglycosides. Subsequent O-phosphitylation, oxidation and deprotection led to the isolation of the target compounds.
