Synthesis of rac-1-(9-o-carboranyl)nonyl-2-methyl-glycero-3-phosphocholine (B-Et-11-OMe), a potential boron carrier for Boron Neutron Capture Therapy (BNCT)

Boron-containing analogues of ether lipids are proposed as boron carriers in the boron neutron capture therapy (BNCT). The synthesis of rac-1-(9-o-Carboranyl)nonyl-2-methyl-glycero- 3-phosphocholine (B-Et-11-OMe) as a first representative is described. The carborane is introduced into the readily assembled glycerol ether moiety. The phosphocholine headgroup is introduced by 2-chloro-3-methyl-1,3,2-λ³-oxazaphospholane using a phosphoamidite strategy and subsequent ring opening under alkylating conditions.