2,2,2-Trichloro-tert-butyl chloroformate → (rac.)-(1R*,5S*)-7-[4-(tert-Butyl-dimethyl-silanyloxy)-phenyl]-3,9-diaza-bicyclo[3.3.1]non-6-ene-3,6,9-tricarboxylic Acid 3-tert-butyl Ester 6-ethyl Ester 9-(2,2,2-trichloro-1,1-dimethyl-ethyl) Ester

Participants

Reaction Conditions

Reaction Steps

A mixture of compound B9 (6.16 g, 11.9 mmol) and 2,2,2-trichloro-1,1-dimethylethyl chloroformate (3.15 g, 13.1 mmol) in 1,2-dichloroethane (200 mL) was heated to 60° C. for 20 h. The mixture was allowed to cool to rt, and the solvents were removed under reduced pressure. Purification of the residue by FC (EtOAc/heptane 8:2) yielded the title compound (7.58 g, 90%). LC-MS: tR=1.29 min, ES+: 707.36.

Provenance & Evidence