Triethylamine → rac-(1R*,4R*)-6-methyl-5-propyl-bicyclo[2.2.2]oct-5-en-2-one

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Reaction Steps

Prepared using the method described in Jung, Michael E.; Tetrahedron Letters 2005, 46(30), 5057-5061. To a suspension of 2.8 g of phosphorous pentoxide in 30 mL anh. DCM were added 6.1 mL of 2-hexanone followed by 14.4 mL of 2-cyclohexen-1-one at rt. The suspension was cooled to 0° C. with an ice bath before 13 mL of trifluoromethanesulfonic acid was carefully added. The reaction mixture was warmed to rt and then heated at 40° C. overnight. 27 mL of NEt3 were dropwise added at 0° C., the mixture was stirred at rt for 10 min and then evaporated to dryness. Purification by CC with EtOAc-Hept (25:75) yielded 3.37 g of rac-(1R*,4R*)-6-methyl-5-propyl-bicyclo[2.2.2]oct-5-en-2-one as brown oil.

Provenance & Evidence