Structure elucidation and conformational properties of synthetic cannabinoids (-)-2-(6a,7,10,10a-tetrahydro-6,6,9-trimethyl-1-hydroxy-6H-dibenzo [b,d]pyranyl)-2-hexyl-1,3-dithiolane and its methylated analog - Mavromoustakos, T.; Theodoropoulou, E.; Zervou, M.; Kourouli, T.; Papahatjis, D. (Journal of Pharmaceutical and Biomedical Analysis, 1999)