(S)-2-(2-Allyloxy-benzoylamino)-3-(4-allyloxy-3-chloro-phenyl)-propionic acid methyl ester → (E)-(S)-19-Chloro-5-oxo-12,17-dioxa-4-aza-tricyclo[16.2.2.0*6,11*]docosa-1(21),6,8,10,14,18(22),19-heptaene-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

In a 250 mL three-necked flask, Grubbs II catalyst (56.3 mg, 66.3 μmol, Eq: 0.30) was combined with dry DCM (50 mL) to give a brown solution. The reaction mixture was heated to 50° C. (reflux) under argon atmosphere. (S)-methyl 3-(4-(allyloxy)-3-chlorophenyl)-2-(2-(allyloxy)benzamido)propanoate (95 mg, 221 μmol, Eq: 1.00) dissolved in dry DCM (30 mL) was added dropwise. The reaction mixture was stirred at 50° C. for 2 h under argon atmosphere. The reaction mixture was stirred for 1 h at 50° C. to drive the reaction to completion. The crude reaction mixture was concentrated in vacuo and purified by flash chromatography (silica gel, 10 g, n-heptane/AcOEt 4/1, 3/1) to yield a brown oil (42 mg; 47%). m/z=402.2 [M+H]+.

Provenance & Evidence