1-(1,1-Dimethylethyl) 2-methyl (2S,4R)-4-fluoro-1,2-pyrrolidinedicarboxylate

A mixture of (2S, 4R)- 1- [(tert-butoxy)carbonyl] -4-fluoropyrrolidine-2-carboxylic acid (2 g, 8.57 mmol), potassium carbonate (5.9 g, 42.69 mmol), THF (80 mL) and CH3I (6.1 g, 42.98 mmol) was stirred for 12 h at room temperature. The solids were filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel eluting with EtOAc/petroleum ether (1:5) to afford the title compound (800 mg, 38percent) as colorless oil.Examples 2-9Preparation of Optically Active Fluoropyrrolidine Derivatives (Ib); (If)Optically active fluoropyrrolidine derivatives (Ib)(If) were prepared by reaction of optically active hydroxypyrrolidine derivatives with an arylsulfur trifluoride in a similar manner as described in Example 1. The optically active hydroxypyrrolidine derivatives and the arylsulfur trifluorides employed in Examples 2-9 are shown in Table 2. The results and reaction conditions are also shown in Table 2 together with those of Example 1. In Examples 3, 6, and 9, the reactions were conducted in the presence of sodium fluoride as a HF-trapping agent (which is shown as an additive in Table 2).

Molecular Weight:247.26
XLogP3:1.6
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:4
Exact Mass:247.12198622
Monoisotopic Mass:247.12198622
Topological Polar Surface Area:55.8
Heavy Atom Count:17
Complexity:313
Defined Atom Stereocenter Count:2
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes