Diisopropylamine → 1,4-Dioxaspiro[4.5]dec-7-en-8-yl trifluoromethanesulfonate

Participants

Reaction Conditions

Reaction Steps

To a solution of diisopropylamine, (6.24 mL, 44.2 mmol) in THF (60 mL) at −78° C. under argon was slowly added n-butyllithium (17.7 mL, 44.2 mmol, 2.5 M in hexanes). The mixture was stirred for 30 min at that temperature before 1,4-cyclohexanedione mono-ethylene ketal (6.00 g, 38.4 mmol) was added slowly as a solution in THF (20 mL). The mixture was stirred for an additional 30 min at −78° C. and then n-phenyltriflamide (13.7 g, 38.4 mmol) was slowly added as a suspension in THF (50 mL). This mixture was stirred overnight with gradual warming to room temperature. The solvent was removed in vacuo and the remaining oil was partitioned between 3:1 ethyl acetate/hexane and water. The layers were separated and the organic layer was washed with water (3×), dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo to give 1,4-dioxaspiro[4.5]dec-7-en-8-yl trifluoromethanesulfonate.

Provenance & Evidence