Chloroform → 77327-04-9

Participants

Reaction Steps

A similar isolation scheme was employed later during large scale production of didemnin B for biological testing. The dichloromethane extract was obtained as before with only minor modifications due to scale-up. Prep LC employed an isocratic chloroform:methanol solvent system ranging from 98:2 to 96:4 depending on the condition of the reusable PrepPak cartridge. This allowed the use of the built-in refractive index detector to monitor elution of the didemnins. Fractions obtained through this procedure were chromatographed on a reversed phase (ODS) PrepPak cartridge with 77:23 methanol:water, again monitoring with the refractive index detector. Pooling of the appropriate fractions gave yields of didemnins A-C similar to those obtained with the original procedure. Didemnins D and E could only be separated by HPLC as above.

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