References
- Rich , D. H. , Jasensky , R. D. , Jueller , G. C. and Anderson , K. E. 1981 . J. Med. Chem. , 24 : 567
- Golding , B. T. and Howes , C. 1984 . J. Chem. Res., Synop. , : 1
- Arnold , L. D. , Kalantar , T. H. and Vederas , J. C. 1985 . J. Am. Chem. Soc. , 107 : 7105
- Waki , M. , Kitajima , Y. and Izumiya , N. 1981 . Synthesis , : 266
- Scholts , J. M. and Bartlett , P. A. 1989 . Synthesis , : 542
- Kjaer , A. 1949 . Acta Chemica Scand. , : 1087
- Grzybowska , J. , Andruszkiewicz , R. and Wojciechowska , H. 1979 . Polish J. Chem. , : 935
- The R and S enantiomers of 2,3-diaminopropionic acid were obtained from American Tokyo Kasei and Schweizerhall, respectively
- The addition of base at low temperature (-78°C) gives optimum results. Addition of base at 0°C leads to formation of 7% of the enantiomer as determined by derivatization of 3a with Marfey's reagent and direct HPLC comparison to the R-enantiomer
- Samples were prepared in methanol at 1 mg per mL and 0.1 mg per mL. Aliquots were dried in a speed vacuum apparatus and redissolved in 500uL of methylene chloride. Ten uL of pyridine and 10 uL of 3,5-dinitrobenzoyl chloride solution (6mg/mL in methylene chloride) was added and the reaction maintained at room temperature for one hour. The methylene chloride was removed in a speed vacuum apparatus under reduced pressure with no heat and redissolved in 500uL methanol. Separation was carried out on a chiral AGP column (100 × 4.0 mm, Advanced Separation Technologies) using an isocratic system of 20 mM sodium monobasic phosphate (75%) and methanol (25%) at 1 mL/min. The column was at room temperature and the effluent was monitored at 254 nM. The S isomer had a retention time of 4.6 minutes, the R isomer a retention time of 5.5 minutes. No R isomer was detected in the product 5 prepared by the above method