Synthesis and crystal structure of-(3 R ,5 S ,10 S ,13 S ,14 S )- N -(4-methoxy-2-methylphenyl)-10,13-dimethylhexadecahydrospiro cyclopenta[ a phenanthrene-17,2′-1,3dioxolan]-3-amine, C 29 H 43 NO 3 | Synapse