(R)-2,2-diallyl-5-(5-bromo-2-fluoro-phenyl)-4-(2,4-dimethoxy-benzyl)-5-methyl-1,1-dioxo-1lambda6-thiomorpholin-3-one → (R)-8-(5-bromo-2-fluoro-phenyl)-9-(2,4-dimethoxy-benzyl)-8-methyl-6,6-dioxo-6lambda6-thia-9-aza-spiro[4.5]dec-2-en-10-one

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Reaction Steps

To a solution of (R)-2,2-diallyl-5-(5-bromo-2-fluoro-phenyl)-4-(2,4-dimethoxy-benzyl)-5-methyl-1,1-dioxo-1λ6-thiomorpholin-3-one (610 mg, 1.08 mmol, Eq: 1.00) in dichloromethane (20.3 ml) was added under argon [1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium (Grubbs II catalyst) (45.7 mg, 53.8 μmol, Eq: 0.05). The reaction mixture was stirred at reflux for 4 hours. Evaporation and chromatography on 20 g silica gel with 0% to 50% ethyl acetate in heptane gave the (R)-8-(5-bromo-2-fluoro-phenyl)-9-(2,4-dimethoxy-benzyl)-8-methyl-6,6-dioxo-6λ6-thia-9-aza-spiro[4.5]dec-2-en-10-one (460 mg, 854 μmol, 79.3% yield) as a white foam. MS (ISP): m/z=538.2 [M+H]+ and 540.2 [M+2+H]+.

Provenance & Evidence