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O+ZHNOONbzOHH +ZHNOOONbzH + OROH R=Z-Ser-ONbzH + 69+ MeOHScheme 2. Mechanism of cleavage MTBE and synthesis of t-butyl ether.In another experiment, reaction of Cl - H 3 N + -Ser-OMe [3] was carried out usingp-toluenesulfonic acid with MTBE or isobutylene, but the yield of the desired ether were10% and 40% respectively. Changing the acid from concentrated inorganic acid to mildsilica sulfuric acid leads to low yield of the product.We described that MTBE could be used as a reagent for tert-butylation of freehydroxy group in serine. The yield using this reagent was lower compared to isobutylene,but it is cheaper and the reaction conditions are mild. The proposed mechanism involvesthe formation of tert-butyl cation and finally formation of O-tert-butylated product. In spiteof the low yield of O-tert-butyl ether with MTBE it has some advantages compared toisobutylene. The simplicity of MTBE as a reagent, low cost of the reagent and mild natureof MTBE compared to isobutylene is an attractive point of the protocol described here. Allof reactions with MTBE were done at room temprature and atmospheric pressure.AcknowledgmentsThis reaction project was supported by Tofigh Daru research company (TODA Co) and we would liketo thank Dr. S. Omidvar and Dr. A. Arabanian for financial support.References1. Reissmann, S., Steinmetzer, T., Greiner, G., Seyfarth, L., Besser, D., Schumann, C. In Synthesis ofPeptides and Peptidomimetics; Eds. Felix, A., Moroder, M., Toniolo, C. Thieme, Stuttgart, 2004,E22A, 347-387.2. Wunch, E., Jentsch, J. Chem. Ber. 97, 2490 (1964).3. Adamson, J., Blaskovich, M.A., Groenevelt, H., Lajoie, G.A. J. Org. Chem. 56, 3447 (1991).