Fmoc-cycloleucine

White powder

1- (((9H-Fluoren-9-yl)methoxy)carbonylamino)cyclopentanecarboxylic acid(compound 4 of example A): Fmoc-OSu (3.13 g, 9.3 mmol) was added to a solution of 1- aminocyclo- pentanecarboxylic acid (1.0 g, 7.8 mmol) and NaHC01- (((9H-Fluoren-9-yl)methoxy)carbonylamino)cyclopentanecarboxylic acid(compound 4 of example A): Fmoc-OSu (3.13 g, 9.3 mmol) was added to a solution of 1- aminocyclo- pentanecarboxylic acid (1.0 g, 7.8 mmol) and NaHC03 (1.63 g, 19.4 mmol) in acetonitrile/water (100 mL, 1 : 1). The reaction mixture was stirred at room temperature overnight. Most of the solvent was removed under reduced pressure and the resulting mixture was adjusted to pH = 2 with 2 N HCI and extracted with DCM. The combined extracts were washed with brine, dried over anhydrous Na2S04 and concentrated. The residue was purified by flash column chromatography on silica gel (PE/EA = 20: 1) to afford compound 4 of example A (0.75 g, 28% yield) as a white solid.General procedure: To 250 mL round-bottomed flask add 1a or 1c or 1g or 1h, 2.5 equiv Fmoc-OSu, 50 mL THF/H2O (1:1, v/v), pH of the solution was adjusted with saturated sodium carbonate to 8-9, and the reaction continued at room temperature for about 18h. After that, the solution was extracted twice with ether, and pH of aqueous layer was adjusted with concentrated HCl to 5, white precipitation was obtain and dried in vacuum to gave corresponding product (2a or 2c or 2g or 2h).

Molecular Weight:351.4
XLogP3:3.7
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:5
Exact Mass:351.14705815
Monoisotopic Mass:351.14705815
Topological Polar Surface Area:75.6
Heavy Atom Count:26
Complexity:520
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes