2-Bornyl 3-methylbutyrate 76-50-6 Bornyl isovalerate Bornyval Butanoic acid, 3-methyl-, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl ester, endo- Hysterol Isovaleric acid, 2-bornyl ester NSC68007