(4E)-2-tert-butyl-6-methylene-9-oxo-(3ar,9ac)-6,7,9,9a-tetrahydro-3aH-oxazolo[4,5-c][1,5]oxazocine-5-carboxylic acid tert-butyl ester 在
silica gel 作用下,
生成 (4
E,6
E)-7-(2,2-dimethyl-propionylamino)-3-methylene-8-oxo-3,8-dihydro-2
H-[1,5]oxazocine-4-carboxylic acid
tert-butyl ester