合成路线1

The title compound was synthesized by coupling two structural moieties. The C/D ring fragment (XII) was prepared as shown in Scheme 28478101a. Indane derivative (I) was protected as the acetate ester (II) and subsequently alkylated at the alpha position of the sulfone group with the chiral tosylate (III) to afford (IV). Reductive cleavage of the sulfone group of (IV) by means of sodium amalgam yielded diol (V), which was protected as the acetonide (VI) using 2,2-dimethoxypropane and p-toluenesulfonic acid. Reprotection of the free hydroxyl group of (VI) as the acetate ester (VII), followed by ketal hydrolysis with iodine in MeOH, produced diol (VIII). This was then silylated with tert-butyldimethylsilyl triflate, giving bis-silyl ether (IX). The acetyl group of (IX) was reductively cleaved with LiAlH4, and the resulting alcohol (X) was oxidized to the corresponding ketone (XI) employing N-methylmorpholine-N-oxide in the presence of tetra-n-propylammonium perruthenate (TPAP). Then, Wittig reaction of ketone (XI) with (bromomethylene)triphenylphosphorane furnished the required bromo olefin (XII).