(5R/S,3aS,7aR)-5-methoxy-hexahydro-2,4-dioxa-7-aza-inden-1-one 、
Fmoc-D-Val-Cl 在
2,6-二甲基吡啶 作用下,
以
二氯甲烷 为溶剂,
反应 3.0h,
生成
(1R,3R,7R,9aS)-1-hydroxymethyl-7-isopropyl-3-methoxy-hexahydro-pyrazino[2,1-c][1,4]oxazine-6,9-dione 、 (1R,3S,7R,9aS)-1-hydroxymethyl-7-isopropyl-3-methoxy-hexahydro-pyrazino[2,1-c][1,4]oxazine-6,9-dione