A Practical Synthesis of (rac)-Muscone and (R)-(–-)-muscone

A practical synthesis of ( rac)-muscone in three steps is described, using commercially available 1,10-dibromodecane as the starting material. In the first step, an aldol reaction of 1,10-dibromodecane with ethyl acetoacetate affords the important intermediate 2,15-hexadecanedione in 70% yield. A cyclisation reaction in the second step aided by propyl zinc iodide gives dehydro-muscone in 84% yield. Hydrogenation of dehydro-muscone with Pd–-C completes the synthesis of ( rac)-muscone. Furthermore, ( R)-(–-)-muscone is enantioselectively prepared via the formation of a ketal intermediate from dehydro-muscone and 1,4-di- O-benzyl- D-threitol.