(3aR,7aS)-2,2-dimethyl-6-oxo-perhydrooxazolo[4,5-c]pyridine-3,5-dicarboxylic acid di-tert-butyl ester 、 alkaline earth salt of/the/ methylsulfuric acid 以
吡啶 、
甲苯 为溶剂,
以86%的产率得到(3aR,7aS)-2,2,6-Trimethyl-3a,7a-dihydro-4H-oxazolo[4,5-c]pyridine-3,5-dicarboxylic acid di-tert-butyl ester