Carbon Dioxide → H-Sta-Ala-Sta-OMe

Participants

Reaction Steps

259 mg of Z-Sta-Ala-Sta-OMe (from stage 13.5) dissolved in 10 ml of 90% strength methanol are hydrogenated in the presence of 30 mg of palladium-on-carbon catalyst (10% Pd) at 25° under normal pressure with CO2 -absorption (CO2 from the removal of the Z-protecting group) until saturation. The catalyst is filtered off, the filtrate is concentrated by evaporation and the residue is dried in a high vacuum. H-Sta-Ala-Sta-OMe is obtained in the form of a colourless foam; Rf (chloroform/methanol/ammonia [40:10:1])=0.41; Rf (C)=0.29.

Provenance & Evidence