Development of the first and practical method for enantioselective synthesis of B-enriched p-borono-l-phenylalanine

At present p-(¹⁰B)borono-l-phenylalanine (l-¹⁰Bpa) is used clinically as an excellent ¹⁰B carrier for BNCT; however, its enantioselective synthesis has not been reported yet. The present Letter describes the first and practical method for enantioselective synthesis of ¹⁰B-enriched l-Bpa using Z-l-Ser-OMe as the chiral synthon in good total yield and high optical purity.     

Designing of the 14 MeV neutron moderator for BNCT

In boron neutron capture therapy (BNCT), the ratio of the fast neutron flux to the neutron flux in the tumor (RFNT) must be less than 3%. If a D-T neutron generator is used in BNCT, the 14 MeV neutron moderator must be optimized to reduce the RFNT. Based on the neutron moderation theory and the simulation results, tungsten, lead and diamond were used to moderate the 14 MeV neutrons. Satisfying RFNT of less than 3%, the maximum neutron flux in the tumor was achieved with a three-layer moderator comprised of a 3 cm thick tungsten layer, a 14 cm thick lead layer and a 21 cm thick diamond layer.