5-isoxazolecarboxylic acid, 2,3-dihydro-2-methyl-3-oxo-, methyl ester InChI=1/C13H18/c1-8-6-11-9-2-3-10(7-9)12(11)13(8)4-5-13/h9-12H,1-7H2/t9-,10+,11+,12-/m1/s rel-(3a'R,4'S,7'R,7a'S)-2'-methyleneoctahydrospiro[cyclopropane-1,1'-[4,7]methanoindene]