you can to disolve d-lame in MeOH and KOH and heat it under inert atmosphere like nitrogen/argon. evaporate the MeOH, then add H2SO4 to drop down the ph in order to crash out and put it in the freezer, filter, redisolve in EtOH and freezer again. after filtration recolect the precipitate and run TLC in order to separate the isomers by disolving in EtOH and eluted with (1:10 heptane, EtOAc)