9-Cyano-2-decalone

The haloketal cyclization is most useful for synthesis of polycyclic systems. Thus (5) is converted into a < b-9-cyano-2-decalone (6), and (7) is converted into (8). The hydrin-dane (10) was prepared from (9). 

Stereospecific conjugate cyanation. By adjusting the reaction conditions, Kelly et al. were able to convert the octalone (1) into either the cis-cyano-decalone (2) or the trans-isomer (3). 

The copper-catalyzed conjugate addition of methyl magnesium iodide to cyclohexenone and trapping the enolate as its trimethylsilyl enol ether, followed by a trityl hexachloro-antinomate-catalyzed Mukaiyama reaction, is apphed to / -(—jcarvone. C-2, C-3 functionalized chiral cyclohexanones are converted into their a-cyano ketones, which are submitted to Robinson annulation with methyl vinyl ketone. Highly functionalized chiral decalones are obtained that can be used as starting compounds in the total synthesis of enantiomerically pure clerodanes (equation 70). 

---