Sodium triacetoxyborohydride → Hydroxy-di-thiophen-2-yl-acetic acid (1S,2R,4S,7S)-7-({9-[(R)-2-(tert-butyldimethyl-silanyloxy)-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethylamino]nonyl}methyl-amino)bicyclo[2.2.1]hept-2-yl ester

Participants

Reaction Steps

A mixture of hydroxy-di-thiophen-2-yl-acetic acid (1S,2R,4S,7S)-7-[methyl-(9-oxo-nonyl)amino]bicyclo[2.2.1]hept-2-yl ester (max 0.73 mmol), 5-[(R)-2-amino-1-(tert-butyldimethylsilanyloxy)ethyl]-8-hydroxy-1H-quinolin-2-one (245 mg, 0.73 mmol), sodium triacetoxyborohydride (186 mg, 0.88 mmol), and acetic acid (2 drops) in dry 1,2-dichloroethane was stirred at ambient temperature overnight. The reaction mixture was partitioned between DCM and satd NaHCO3 (aq). The organic layer was dried (Na2SO4), filtered, and concentrated in vacuo to afford a dark green/brown gum that solidified on standing, which was purified by preparative HPLC (system 2, 35% B+1% B/min). The fractions containing pure product were concentrated, neutralised with satd NaHCO3 (aq), and extracted with DCM. After concentration in vacuo a green/brown oil was obtained.

Provenance & Evidence