反应详情

温度

100 °C

0.5 mmoles 1-acetoxy-3-methylthiopropene, (Z: E ratio 43:57), and 2.5 mmoles methanol were charged into a 71 cc stainless steel bomb equipped with a glass liner and a Teflon coated stir bar. Ten mole percent, based on 1-acetoxy-3-methylthiopropene, of a catalyst comprising Pd(Pφ3)4 plus 10 mole percent HCl co-catalyst was added. Toluene was included as an internal standard Five milliliters of tetrahydrofuran as a solvent were also included in the reaction system. The reaction mixture was charged under argon. The bomb was sealed and carbon monoxide at a pressure of 1000 psi (at room temperature) was charged to the bomb, and the bomb was heated to 100° C. and allowed to react for 45.25 hours with stirring. At the termination of the reaction, the reaction products were analyzed by gas chromatography and it was found that 2-acetoxy-4-(methylthio)butanoic acid, methyl ester was produced in a yield of 21.7 percent, and that 2-acetoxy-4-(methylthio)thiobutanoic acid, methyl ester was produced in a yield of 17.8 percent, based on the 1-acetoxy-3-methylthiopropene reactant charged. Note that each of the products is hydrolyzable to methionine hydroxy analog. When this run was repeated without the HCl co-catalyst (run length 44 hours), the yields of the above ester and thioester were3 93 percent.and 4.48 percent, respectively.

1. customequipped with a glass liner and a Teflon coated stir bar
2. additionwas added
3. additionThe reaction mixture was charged under argon
4. customThe bomb was sealed
5. customto react for 45.25 hours
6. customAt the termination of the reaction
7. customwas produced in a yield of 21.7 percent