Cis-g-Irone's syntheses


    The cis isomers and especially cis-g-irone are responsible in the powerful and pleasant violet-like olfactive properties.
    The synthesis of irones has attracted considerable attention over the last 20 years.
    The cis-g-irone's syntheses, excepted one, are not stereoselective and consequently the major product  is   trans-g-irone. Moreover, these isomers are not separated on a preparative scale.

            Summary: There are 5 cis-g-irone's syntheses, and only one with total stereoselectivity.
 
 


Which are the difficulties?

 a) The introduction of cis stereochemistry .

 b) Diastereoisomers intermediates are rarely separated. 
Our Solutions to the synthesis:

1) Amelioration to the literature's key intermediate.

2) An highly diastereoselective protonation.
 

 

 The different syntheses are based upon 4 strategies: (see below, and click on a pathway)

click on a pathway