ASYMMETRIC-SYNTHESIS OF CARBORANYL AMINO-ACIDS WITH POTENTIAL USE IN BNCT

Two alpha-amino acids containing the 1,2-dicarba-closo-dodecaborane (1 2) cage, namely, 5-(1,2-dicarba-closo-dodecaboran (12)-1-yl)-2-aminope ntanoic acid (1) and 5-(2-methyl-1 (2-dicarba-closo-dodecaboran (12)-1 -yl)-2-aminopentanoic acid (2), were prepared by asymmetric synthesis (e.p.>98%) by using the chiral glycine equivalent, imidazolidinone 3, introduced by Seebach. and Oppolzer's camphor-derived sultam derivativ e 4. The dextrorotatory enantiomers (sodium D line in methanol) of the amino acids 1 and 2 were both shown to have (S) configuration.