Tri-tert-butylphosphine tetrafluoroborate → methyl (1aRS,7bSR)-5-{N-[methoxycarbonyl]-N-[2-((Z)-3-hydroxyprop-1-enyl)-4-fluorobenzenesulfonyl]amino}-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Participants

Reaction Steps

A mixture of methyl (1aRS,7bSR)-5-[N-(2-bromo-4-fluorobenzenesulfonyl)-N-(methoxycarbonyl)amino]-1,1a,2,7b-tetrahydrocyclopropa-[c]chromene-4-carboxylate (Intermediate 65, 0.6 g), (Z)-3-tributylstannanylprop-2-en-1-ol (Intermediate 12, 0.81 g), tris-(dibenzylideneacetone)dipalladium (0.1 g) and tri-tert-butylphosphonium tetrafluoroborate (0.07 g) in dioxane (18 mL) and DMSO (2 mL) was stirred at room temperature for 30 minutes. The resultant mixture was diluted with ethyl acetate and washed with water, dried (Na2SO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and petroleum ether with a gradient of 30-50% to give methyl (1aRS,7bSR)-5-{N-[2-((Z)-3-hydroxyprop-1-enyl)-4-fluorobenzenesulfonyl]-N-[methoxycarbonyl]amino}-1,1a,2,7b-tetrahydrocyclopropa-[c]chromene-4-carboxylate (0.55 g) as an off-white solid.

Provenance & Evidence