L-Pyroglutamic Acid → HCID 57699455, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (3R,6S)-(6-hydroxymethyl-tetrahydro-pyran-3-yl)-carbamic acid tert-butyl ester (37.5 g, 162.13 mmol) in DCM (310 mL) cooled to −10° C. was added DIPEA (84.75 mL, 495.06 mmol). Then a solution of Pyr.SO3 complex (50%, 69.47 g, 218.25 mmol) in DMSO (225 mL) was slowly added. The reaction mixture was stirred for 2 h at 0° C. The reaction mixture was partitioned between water (150 mL) and DCM (220 mL). The two layers were separated and the aq. layer was extracted twice with DCM (2×150 mL). The combined org. layers were dried over Na2SO4, filtered and concentrated to dryness. The residue was co-evaporated 3 times with toluene and purified over a short pad of silica gel (EA-Hept. 2-1) to afford the title aldehyde as a white solid (33.58 g, 90% yield).

Provenance & Evidence