D-Proline, 4-hydroxy-, methyl ester, hydrochloride (1:1), (4R)-

To a stirred solution [OF 4R-HYDROXYPYRROLIDINE-2R-CARBOXYLIC] acid (10.0 g, 76.3 mmol, [1] eq. ) in [MEOH] (300 mL) at [0 °C] was added SOC12 (10.0 mL, excess) over the course of 1.5 min. The reaction was allowed to warm to [23 °C.] After 16 h the reaction mixture was concentrated in vacuo to give 4R-hydroxypyrrolidine-2R-carboxylic acid methyl ester hydrochloride salt as a white solid (15.9 g, 100percent yield)To a solution of (2R, 4R)-4-hydroxypyrrolidine-2-carboxylic acid 31.1 (1.0 eq) in MeOH (31 eq) at 0 °C was added S0C1To a suspension of (2R, 4R)-4-hydroxypyrrolidine-2-carboxylic acid (100 g, 0.763 mol) in MeOH (1 L) was added SOd2 (115 g, 0.966 mcI) slowly at 10 °C. Then the reaction was heated at 65 °C for 2 hrs. The mixture was concentrated under high vacuum. The residue was washed with ether, filtered to give the title compound 0350 (138 g, 100percent yield) as a yellow solid.LCMS: 146 [M+H]. tR =0.366 mins. (LCMS condition 3)Step A-1. Cis-4-hydroxy-D-proline hydrochloride 3A (12.8 g, 76.38 mmol) was dissolved in anhydrous methanol (120 mL) at room temperature, Cooled to 0 , dichloro sulfoxide (10.27g, 86.31mmol), Heated to 75 ° C, refluxed for 4.5 hours, and allowed to react overnight at room temperature.The solvent was taken off in vacuo to give a white solid 3B (13.83 g, yield 100percent).

Molecular Weight:181.62
Hydrogen Bond Donor Count:3
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:2
Exact Mass:181.0505709
Monoisotopic Mass:181.0505709
Topological Polar Surface Area:58.6
Heavy Atom Count:11
Complexity:137
Defined Atom Stereocenter Count:2
Covalently-Bonded Unit Count:2
Compound Is Canonicalized:Yes