Hydrochloric Acid → HCID 86742519, compound

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence