Bis(4-chlorobutyric acid)(1aR)-1,1aα,1bβ,4,4a,5,7aα,7b,8,9-decahydro-4aβ,7bα-dihydroxy-3-(hydroxymethyl)-1,1,6,8α-tetramethyl-5-oxo-9aH-cyclopropa[3,4]benz[1,2-e]azulene-9β,9aα-diyl ester