合成路线1

Reduction of dibenzosuberenone (I) with in situ generated AlH3 affords dibenzocycloheptene (II). Subsequent epoxidation of (II) employing m-chloroperbenzoic acid gives the dibenzocycloheptaoxirane (III) (1). Epoxide ring opening in (III) with allylmagnesium bromide produces the trans alcohol (IV). Bromination of the double bond of (IV) with pyridinium tribromide leads to the trans-fused tetrahydrofuran derivative (V) as a mixture of 4 diastereoisomers. Then, substitution of the bromide ion of (V) with dimethylamine, followed by chromatographic separation of the isomers provides the target compound.