Toluene → tert-butyl (4S,7S,10aS)-5-oxo-7-vinyloctahydro-2H-pyrido[2,1-b][1,3]thiazepin-4-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of methyltriphenoxyphosphonium iodide (716 mg, 1.58 mmol) in dry THF (5 mL) under argon at 0° C. was added dropwise a solution of 0.5 M potassium hexamethyldisilazide in toluene (3.17 mL, 1.58 mmol). The reaction mixture was stirred for 10 min at 0° C. and then for 20 min at rt. Then, the reaction temperature was lowered to −78° C. and a solution of tert-butyl (4S,7S,10aS)-7-formyl-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepin-4-ylcarbamate (400 mg, 1.22 mmol) in dry THF (5.00 mL) was added. The reaction mixture was stirred for 3 hr at rt. The reaction mixture was diluted with saturated aqueous NH4Cl (100 mL) and extracted with EtOAc (2×40 mL). The combined EtOAc layers were washed with water, saturated aqueous NaCl, dried over Na2SO4, filtered & concentrated. The residue was purified using silica gel chromatography (ISCO system) eluting with a gradient of 0-30% EtOAc/Hex to give tert-butyl (4S,7S,10aS)-5-oxo-7-vinyloctahydro-2H-pyrido[2,1-b][1,3]thiazepin-4-ylcarbamate (360 mg, 1.10 mmol, 91% yield) as a white foam. 1H NMR (400 MHz, CDCl3) δ ppm 6.48-6.18 (m, 1H), 6.07-5.81 (m, 1H), 5.50-5.22 (m, 2H), 5.22-4.99 (m, 2H), 4.92-4.69 (m, 1H), 3.20-2.98 (m, 1H), 2.85-2.61 (m, 1H), 2.49-2.26 (m, 1H), 2.17-1.96 (m, 2H), 1.96-1.65 (m, 4H), 1.66-1.52 (m, 1H), 1.43 (s, 9H).

Provenance & Evidence