(S)-3-tert-Butoxy-2-[2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-5-oxo-pentanoylamino]-propionic acid tert-butyl ester 在
对甲苯磺酸 作用下,
以
甲苯 为溶剂,
反应 1.0h,
生成 (S)-3-tert-Butoxymethyl-6-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-tetrahydro-oxazolo[3,2-a]pyridine-2,5-dione 、 (S)-6-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-5-oxo-hexahydro-oxazolo[3,2-a]pyridine-3-carboxylic acid tert-butyl ester 、
(αS,3RS)-N-[1-(tert-butoxycarbonyl)-2-tert-butoxyethyl]-3-phthaloyl-Δ5-piperidein-2-one