(3aS,7aS)-2-Allyl-1,3-bis(4-bromobenzyl)-2-chlorooctahydro-1H-benzo[d][1,3,2]diazasilole → (R)-4-((R)-1-hydroxybut-3-enyl)-1-((R)-1-(4-methoxyphenyl)ethyl)pyrrolidin-2-one

Participants

Reaction Steps

To a solution of (R)-1-((R)-1-(4-methoxyphenyl)ethyl)-5-oxopyrrolidine-3-carbaldehyde 1.07 (0.93 g, 3.76 mmol) at rt was added (S,S)-2-allyl-1,3-bis-(4-bromobenzyl)-2-chlorooctahydro-2-1H-1,3,2-benzodiazasilole (3.338 g, 6.02 mmol) followed by Sc(III) triflate (0.093 g, 0.188 mmol). The reaction was stirred at rt for 1.5 hr and the solvent was removed. To the residue was added Et2O (80 mL) and 1M HCl (20 mL). The suspension was stirred for 1 hr and the solids were removed by filtration. The filter cake was washed with ether. The filtrate was transferred to a separatory funnel and the layers were separated. The aqueous layer was further extracted with Et2O (3×40 mL). The combined organics were dried (MgSO4), filtered and concentrated. The residue was purified by flash chromatography to afford (R)-4-((R)-1-hydroxybut-3-enyl)-1-((R)-1-(4-methoxyphenyl)ethyl)pyrrolidin-2-one 1.08.

Provenance & Evidence