Picolinic acid → HCID 11589598, compound

Participants

Reaction Steps

To a solution of 2.2.c (R=Me, P=TBDPS, A=COOCH3) (167 mg, 0.392 mmol), picolinic acid (257 mg, 2.092 mmol) and triphenylphosphine (548 mg, 2.092 mmol) in THF at −38° C. was added dropwise DIAD (diisopropyl azodicarboxylate; 412 μL, 2.092 mmol) over 4 min. The reaction solution was stirred for 4.5 h and warmed to room temperature overnight. The mixture was poured into water and EtOAc (50 ml:50 ml). The organic phase was separated, the aqueous layer was extracted with EtOAc (3×50 ml) and dried over MgSO4. The residue was separated by HPLC (isooctane/EtOAc 98:2), affording (4S,6S)-4-carbomethoxy-6-t-butyldiphenylsilyloxy-1-methylcyclohexene (142 mg, 88.8%) as a colorless oil.

Provenance & Evidence