A new strategy for the synthesis of taurine derivatives using the 'safety-catch' principle for the protection of sulfonic acids.
The safety-catch principle has been applied for the development of a new method for protecting sulfonic acids. 2,2-Dimethylsuccinic acid was reduced to 2,2-dimethylbutane-1,4-diol, which was selectively silylated to give 4-(tert-butyldiphenylsilanyloxy)-2,2-dimethylbutan-1-ol. Reaction of the latter compound with 2-chloroethanesulfonyl chloride in the presence of triethylamine afforded 4-(tert-butyldiphenylsilyloxy)-2,2-dimethylbutyl ethenesulfonate directly. The ethenesulfonate underwent Michael-type addition with secondary amines to give protected derivatives of taurine (2-aminoethanesulfonic acid). Deprotection was achieved on treatment with tetrabutylammonium fluoride, whereby cleavage of the silicon-oxygen bond led to an intermediate alkoxide that immediately cyclised to 2,2-dimethyltetrahydrofuran with liberation of a sulfonate. Pure sulfonic acids were obtained from the crude product by ion exchange chromatography on a strongly basic resin, which was eluted with aqueous acetic acid. The method developed should be generally applicable to the protection of sulfonic acids and is amenable to a multiparallel format.
Seeberger
Sonja
S
Northern Institute for Cancer Research, School of Natural Sciences-Chemistry, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom.
Griffin
Roger J
RJ
Hardcastle
Ian R
IR
Golding
Bernard T
BT
D015394:Molecular Structure; D013451:Sulfonic Acids / Q000737:chemistry*; D013654:Taurine / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry
D013451:Sulfonic Acids; D013654:Taurine