Yield:1198355-16-6 80%

Reaction Conditions:

with potassium tert-butylate in tetrahydrofuran at 20; for 1 h;Inert atmosphere;

Steps:

B B. tert-Butyl ((trans)-4-vinylcyclohexyl)carbamate

To an ice-cold suspension of methyltriphenylphosphonium bromide (5.03 g, 14.08 mmol) in THF (25 mL), under N₂, was added potassium tert-butoxide (1.580 g, 14.08 mmol) in portions. After 5 min, the ice bath was removed and the mixture was stirred at rt. After ~1 h, tert-butyl ((trans)-4-formylcyclohexyl)carbamate (1.6 g, 7.04 mmol) was added. The mixture was stirred at rt for ~1 h, and then, aq. satd. NH₄CI solution (~10 mL) was slowly added. The mixture was partitioned between EtOAc and water. The aqueous phase was washed 1X with EtOAc. The combined organic phases were washed 1X with brine, dried over Na₂S0₄, filtered, and concentrated. The residue was purified by silica gel chromatography, eluting with 0-50% EtOAc:hexanes gradient (fractions were checked with PMA stain) to give tert-butyl ((trans)-4-vinylcyclohexyl)carbamate (1.329 g, 5.60 mmol, 80% yield) as a white solid. ¹H NMR (400 MHz, CD₃SOCD₃) d ppm 6.72 (d, J = 8 Hz, 1 H), 5.66- 5.86 (m, 1 H), 4.97 (dd, J = 17, 2 Hz, 1 H), 4.89 (dd, J = 10, 2 Hz, 1 H), 3.05-3.22 (m, 1 H), 1.74-1.94 (m, 3 H), 1 .65-1.72 (m, 2 H), 1.38 (s, 9 H), 1.00-1.27 (m, 4 H).

References:

WO2019/116256,2019,A1 Location in patent:Page/Page column 66; 67