Diazomethane → (2S,4R)-4-Hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

Participants

Role	Name	HCID	Charge
Reactant	Diazomethane	HCID 9550	—
Reactant	(2S,4R)-4-hydroxy-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acid	HCID 88804	—
Solvent	Tetrahydrofuran	HCID 8028	—
Product	(2S,4R)-4-Hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester	HCID 2734883	96.1%

Reaction Steps

To a solution of compound 235 (5.2 g, 22.49 mmol) in THF (50 mL) was added diazomethane (38.5 mL, 27.0 mmol, 0.7M) dropwise until yellow color persists. The mixture was concentrated to afford title compound 236 (5.3 g, 96%) as a clear oil. 1H NMR (400 MHz, CDCl3) δ (ppm): 4.50-4.47 (m, 1H), 4.44 (t, J=7.7 Hz, 1H), 3.76-3.43 (m, 2H), 3.73 (s, 3H), 2.33-2.22 (m, 1H), 2.11-2.03 (m, 1H), 1.91 (m, 1H), 1.45-1.41 (m, 9H). LRMS (ESI): (calc.) 245.13. (found) 146.0 (M-Boc+H)+.

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US09193749B2
Source dataset	uspto-grants-2015_11
ORD ID	ord-78b17a8c048945b193d01e15796d890a
Source note	uspto-grants-2015_11