Crystal structure of (1aα,2α,5β,8α,8aα)-2,3,8-trichloro-1a,2,5,6,8,8a-hexahydro-5-methoxy-9-oxo-2,8-methano-1H-cyclopropa[4,5]cyclohepta- [1,2-]pyran, (С9Н4OСl3)[С3Н4O(OСН3)]