2-Hydroxy-2,3-dimethyl-butyric acid 7-hydroxy-5,6,7,7a-tetrahydro-3H-pyrrolizin-1-ylmethyl ester InChI=1/C14H23NO4/c1-9(2)14(3,18)13(17)19-8-10-4-6-15-7-5-11(16)12(10)15/h4,9,11-12,16,18H,5-8H2,1-3H3/t11-,12-,14+/m1/s O9-(2S-2-Hydroxy-2,3-dimethyl-butanoyl)-retronecine O9-(2S-2-Hydroxy-2,3-dimethylbutanoyl)retronecine Retrohoustine [(1R,7aR)-1-hydroxy-2,3,5,7a-tetrahydro-1H-pyrrolizin-7-yl]methyl rel-(2S)-2-hydroxy-2,3-dimethylbutanoate butanoic acid, 2-hydroxy-2,3-dimethyl-, [(1R,7aR)-2,3,5,7a-tetrahydro-1-hydroxy-1H-pyrrolizin-7-yl]methyl ester, (2S)-