VF8 vf8 (3R,6R,7S,8E,11S,12R,22S)-6'-chloro-7-methoxy-11,12-dimethyl-13,13-dioxo-spiro[20-oxa-13-gamma6-thia-1,14-diazatetracyclo[14.7.2.03,6.019,24]pentacosa-8,16(25),17,19(24)-tetraene-22,1'-tetralin]-15-one VF8