2-Nitrogalactal derivative 1 afforded 2-deoxy-2-nitrogalactopyranosides on treatment with phenol and substituted derivatives under base catalysis. Transformation of the nitro group into the amino and the acetamido groups and O-deprotection could readily be performed, thus providing aryl 2-acetamido-2-deoxygalactopyranosides 5 and 6 in high yields and with good stereoselectivities. The same reaction
2-硝基半乳醛衍
生物 1 在碱催化下用
苯酚和取代衍
生物处理得到 2-脱氧-2-硝基半
乳糖苷。可以很容易地将硝基转化为
氨基和乙酰
氨基和 O-脱保护,从而以高产率和良好的立体选择性提供芳基 2-乙酰
氨基-2-脱氧
吡喃半
乳糖苷 5 和 6。同样的反应顺序也可以成功应用于 N-Boc 保护的
酪氨酸甲酯,得到 O-
吡喃半
乳糖基
酪氨酸衍
生物 10。 (© Wiley-
VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)