2,2-Dimethyl-1,3-dioxan-5-amine

To a dry (0408) 200 round-bottomed flask was added di(2-pyridyl) thionocarbonate (3.72 g, 16.01 mmol) in DCM (50.8 mL). 2, 2-Dimethyl-l, 3-dioxan-5-amine (commercially available from ChemBridge, 2 g, 15.25 mmol) in DCM (15 mL) was added dropwise via an addition funnel over 5 min at RT with stirring. The reaction mixture was stirred at 23 °C for 3 h. The reaction mixture was then concentrated in vacuo. The material initially obtained was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (40 g), eluting with a gradient of 0percent to 50percent EtOAc in heptane to provide Example 1.1 (2.5 g, 14.43 mmol, 95 percent yield) as a colorless oil. NMR (400 MHz, CDC13) delta 1.43 (s, 3 H) 1.47 (s, 3 H) 3.55 (tt, J=5.07, 3.43 Hz, 1 H) 3.87 (dd, J=12.13, 5.08 Hz, 2 H) 4.08 (dd, J=12.02, 3.42 Hz, 2 H). LCMS-ESI (pos.) m/z: 174.2 (M+H)+.To a solution of 10287] In a typical run, (R)-2-amino-3-mercapto-3-meth- ylbutanoic acid (0.454 g, 3.05 mmol, 1 eq) and 4-phenyl- butyric acid (0.5 g, 3.05 mmol, 1 eq) were taken up in DMF (10 mE). HATU (1.51 g, 3.96 mmol, 1.3 eq) and Et3N (0.924 g, 9.15 mmol, 3 eq) were then added. The resulting reaction mixture was stirred at room temperature for 16 h under an inert atmosphere of nitrogen. The reaction mixture was extracted with EtOAc. The combined organic layers were washed with water and brine, dried over anhydrous Na2SO4 and concentrated under reduced pressure. The resulting residue was purified by preparative HPLC to afford (R)-3- mercapto-3-methyl-2-(4-phenylbutanamido)butanoic acid (0.35 g, 39percent yield) as a yellow oil. This material (0.35 g, 1.19 mmol, 1 eq) was taken up in DMF (5 mE) and

Molecular Weight:131.17
XLogP3:-0.5
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:131.094628657
Monoisotopic Mass:131.094628657
Topological Polar Surface Area:44.5
Heavy Atom Count:9
Complexity:93.2
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes