Phthalimide → (R)-tert-butyl benzyloxy(1-(1,3-dioxoisoindolin-2-yl)but-3-en-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A suspension of (R)-tert-butyl benzyloxy(1-hydroxybut-3-en-2-yl)carbamate (Intermediate 154, 74 g, 252.25 mmol), phthalimide (66.8 g, 454.02 mmol) and triphenylphosphine (119 g, 453.70 mmol) in toluene/THF (200/200 mL) was cooled under nitrogen with ice. DIAD (91.8 g, 453.98 mmol) was added dropwise over 20 minutes and the mixture was stirred at 0° C. for 20 minutes, without cooling for 2 hr. The mixture was filtered and the filtrate was evaporated. The residue was taken up in ether and filtered. The filtrate was evaporated and the residue was purified by silica gel column and eluted with EtOAc/hexane (0-50%) to give the title compound (74 g, 79%) as a colorless oil.

Provenance & Evidence