[(S)-1-(Methoxy-methyl-carbamoyl)-2-methyl-propyl]carbamic acid benzyl ester → benzyl [(1S)-1-formyl-2-methylpropyl]carbamate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of [(S)-1-(Methoxy-methyl-carbamoyl)-2-methyl-propyl]-carbamic acid benzyl ester (8) (33 g, 112 mmol) in dry THF (300 mL) at −30 to −40° C. was added LiAlH4 (4.3 g, 113 mmol) portion wise over a period of 45 min. The reaction mixture was warmed to 0° C. and stirred at this temperature for 2 h. The reaction mixture was quenched with 1 M KHSO4 (330 mL) at 0° C. then 10% w/v Rochelle's salt (aq) (330 mL) was added and the mixture stirred for 20 minutes, then extracted with EtOAc (2×700 mL). The combined organic phases were washed with 10% w/v Rochelle's salt (aq) (330 mL) and brine (450 mL), dried over MgSO4, filtered and concentrated under vacuum to obtain the desired aldehyde as a clear oil (26.3 g) (AnalpH2_MeOH—4 min) Rt 2.59 min; m/z 236 (MH)+. (This was used without further purification in the next step.)

Herkunft & Nachweise