(3S,4S,9aβ,9aβ)-6α,6α-Di-(3-furyl)-1,6,7,8,9,9a,1,6,7,8,9,9a-dodecahydro-9β,9β-dimethyldispiro[2H-quinolizine-3(4H),2(3H)-thiophene-4(5H),3(4H)-[2H]quinolizine]