CYCLIC SULFATES - USEFUL SUBSTRATES FOR SELECTIVE NUCLEOPHILIC-SUBSTITUTION
CYCLIC SULFATES - USEFUL SUBSTRATES FOR SELECTIVE NUCLEOPHILIC-SUBSTITUTION
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DOI：
10.1021/jo00291a020
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发表时间：
1990-02-16
影响因子：
3.6
通讯作者：
TEWSON, TJ
中科院分区：
文献类型：
--
作者：
BERRIDGE, MS;FRANCESCHINI, MP;TEWSON, TJ
研究了环状硫酸盐与氟离子、苯氧离子和高比活度[18F]氟化物的反应。通过合成和高锰酸盐氧化相应的亚硫酸盐来制备低分子量无环二醇的环状硫酸盐。亚硫酸盐不是很好的替代底物。包括含有五元、六元和七元环的环状硫酸酯。3-O-乙酰基雌醇、甲基4，6-O-亚苄基吡喃葡萄糖苷和甲基4，6-O-亚苄基-β-吡喃葡萄糖苷的环状硫酸酯的反应包括各自通过二醇与磺酰氯反应产生的甘露吡喃糖苷。环状硫酸酯与亲核试剂在乙腈中的反应在几分钟内完成。环状硫酸酯上的亲核反应对空间和电子方向都很敏感。酚盐的空间方向是几乎完全regiospecific的，和氟化物的掺入表现出明显的regiospecific。环状二醇的硫酸盐表现出最大程度的空间位阻控制。环状硫酸酯基团似乎是同时促进亲核反应和保护附近羟基官能团的通常有用的手段。
The reactions of cyclic sulfates were studied with fluoride ion, phenoxide ion, and high specific activity [18F]fluoride. Cyclic sulfates of low molecular weight acyclic diols were produced by synthesis and permanganate oxidation of the corresponding sulfites. The sulfites were not good substrates for substitution. Cyclic sulfates containing five-, six-, and seven-membered rings were included. Reactions of cyclic sulfates of 3-O-acetylepiestriol, methyl 4,6-O-benzylideneglucopyranosides, and methyl 4,6-O-benzylidene-.beta.-mannopyranoside, each produced by reaction of a diol with sulfuryl chloride, were included. The reaction of cyclic sulfates with nucleophiles was complete in minutes in refluxing acetonitrile. The nucleophilic reactions on cyclic sulfates are sensitive to steric and electronic direction. Steric direction of phenoxide was nearly completely regiospecific, and incorporation of fluoride showed pronounced regioselectivity. Sulfates of cylic diols showed the greatest degree of steric control. The cyclic sulfate group appears to be a generally useful means of simultaneously facilitating nucleophilic reactions and protecting nearby hydroxyl functions.