2-propyl-1,3-dithiane → HCID 15615041, compound

Participants

Reaction Steps

n-Butyl lithium (2.5M, 11.76 ml, 29.4 mmol) was added dropwise at -25° to a 40 ml tetrahydrofuran solution of 2-n-propyl-1,3-dithiane from part A (4.536 g, 28.0 mmol). After stirring for 2 hours at -20° to -25°, the solution was cooled to -78° and (S)-<α-[[(1,1-dimethylethoxy)carbonyl]amino]cyclohexanepropanal (3.57 g, 14.0 mmol) was added as a 20 ml tetrahydrofuran solution. A chromatography check after 1 hour revealed the formation of a complex reaction mixture. It was warmed gradually from -78° to -50° over a period of 18 hours, quenched with saturated ammonium chloride (50 ml) and the two layers separated upon warming to room temperature. The aqueous layer was diluted with water (75 ml, to dissolve the precipitated ammonium chloride) and reextracted with ethyl acetate (2×50 ml). Combined organic extracts were washed with saturated ammonium chloride (1×75 ml), dried over anhydrous sodium sulfate and concentrated to give 7.9 g crude product which upon flash chromatographic purification yielded 1.517 g of the title B compound.

Provenance & Evidence