Tetrahydrofuran → (3S,4R)-3-[1-(R)-t-Butyldimethylsilyloxyethyl]-4-(2-p-nitrobenzyloxycarbonylaminoethyl)thiomethylcarbonylmethylazetidin-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

0.536 g. of 2-(p-nitrobenzyloxycarbonylamino)ethylmercaptan was added to a mixture of 0.635 g. of bromomethylazetidin-2-one (48) and 20 ml. of dry tetrahydrofuran. The mixture was cooled to -78° C. and a solution of 1.18 ml of n-butyllithium in n-hexane was added thereto. The mixture was stirred at that temperature for 1.5 hours. Acetic acid (0.22 ml) was added to the reaction mixture. The mixture was then diluted with 380 ml of ethyl acetate and washed successively with water and an aqueous solution of sodium chloride, and was then dried over sodium sulphate. The solvent was distilled off under reduced pressure and the resulting oily residue was subjected to rapid chromatography using silica gel eluted with a 1:4 by volume mixture of benzene and ethyl acetate, to afford 0.718 g. (yield 76.3%) of the desired azetidin-2-one (49).

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