7-Bromo-1-heptene → Tert-butyl 1-(hept-6-enyl)cyclopropylsulfonylcarbamate

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Reaction Steps

To a solution of tert-butyl cyclopropylsulfonylcarbamate (885 mg, 4 mmol) in THF (20 mL) at −78° C. was added n-Butyllithium (3.36 mL, 8.40 mmol) (2.5 M in hexanes) dropwise. The formed solution was warmed up to r.t. and stirred for 1.5 h. Cooled this light yellow solution back to −78° C. 7-Bromo-1-heptene (1.219 mL, 8.00 mmol) was added dropwise. The final solution was allowed to warm up to r.t. over the period of 16 h. Quenched with sat. NH4Cl, extracted with EtOAc. The organic layer was washed with brine, dried over MgSO4, filtered, and concentrated. The residue was purified by Biotage column, eluted with gradient 5%˜40% EtOAc-Hexane to afford the desired product tert-butyl 1-(hept-6-enyl)cyclopropylsulfonylcarbamate (625 mg, 1.772 mmol, 44.3% yield) as a viscous oil, which solidified upon standing on bench. 1H NMR (400 MHz, CHLOROFORM-D) ppm 0.88-1.02 (m, 2 H) 1.26-1.49 (m, 6 H) 1.53 (s, 9 H) 1.60-1.71 (m, 2 H) 1.82-1.94 (m, 2 H) 2.06 (q, J=6.94 Hz, 2 H) 4.81-5.08 (m, 2 H) 5.68-5.88 (m, 1 H) 6.88 (b, NH). LC-MS (retention time: 2.76 min, Method A), MS m/z 218 (M+H-Boc).

Provenance & Evidence