(S)-4-tert-butyl 1-((R)-2-pent-4-enamido-2-phenylethyl) 2-allylsuccinate → tert-butyl 2-((3R,11S,E)-5,12-dioxo-3-phenyl-1-oxa-4-azacyclododec-8-en-11-yl)acetate

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-4-tert-butyl 1-((R)-2-pent-4-enamido-2-phenylethyl) 2-allylsuccinate (340 mg, 0.818 mmol) in toluene (82 mL) was added Grubbs 2nd Generation catalyst (34.7 mg, 0.041 mmol) and the reaction mixture was heated to 65° C. Upon stirring 7 h with continued heating, TLC analysis indicated complete consumption of starting material. The reaction mixture was cooled to rt, diluted with degassed CH2Cl2 (8.2 mL) and Pb(OAc)4 (181 mg, 0.409 mmol) was added. The resultant mixture was stirred for 12 h at which point the mixture was passed through a short plug of silica then concentrated using rotary evaporation. The resulting purple solid was triturated with methanol to further remove ruthenium complexes. The off white solid that remained was purified using silica gel chromatography (MeOH/CH2Cl2 gradient) to yield 130 mg of desired product as a white solid in 41% yield. LRMS (M+Na)+: 410.4.

Provenance & Evidence