Methanol → HCID 54303873, compound

Participants

Reaction Steps

Potassium hexamethyldisilazane (10.8 mL of a 1.85M solution in THF, 20 mmol) was added over 15 minutes to a stirred mixture of n-butyl triphenyl-phosphonium bromide (7.99 g., 20 mmol) and THF (75 mL) at 0°. After addition was complete, the mixture was stirred at 0° for 30 minutes and then a solution of (S)-2-methyl-4-(tert. butoxycarbonylamino) pentanal (2.04 g, 9.48 mmol) in toluene (10 mL) was added over 15 minutes. The reaction mixture was stirred at 0° for 30 minutes, 20°-25° for 30 minutes and then at 40° for 18 hours. Methanol (1 mL) then H2O (5 mL) were added and solvents removed under reduced pressure at 40°. The residue was partitioned between ethyl acetate and a dilute solution of Rochelle's salt. The ethyl acetate extract was washed with brine, dried (Na2SO4), filtered and concentrated. Flash chromatography of the residue over silica gel and elution with 10% ethyl acetate 90% hexane gave 2.10 g of product.

Provenance & Evidence