Tagetones synthesis

Methyl-5-hepten-2-one is an important intermediate in the synthesis of terpenoids. Its odor properties are not impressive. It occurs in nature as a decomposition product of terpenes. Tagetone [6752-80-3] is a major component of tagetes oil. Solanone [1937-45-8] and pseudoionone [141-10-6] are acyclic Cn ketones with a terpenoid skeleton. Solanone is one of the flavor-determining constituents of tobacco, pseudoionone is an intermediate in the synthesis of ionones. 

An interesting variant of these Michael-type additions is the 1,6-addition of the anion of type (29) to a dienyl sulfone as a route to tagetones and 1,4-addition to nitrostyrene to form 3-nitro ketones. A key step in a synthesis of 11-deoxyanthracyclinone involves the regioselective reaction of complexed styrene with lithiated protected acetddehyde cyanohydrin. ... 

Many functional groups are tolerated during the Friedel-Crafts acylation of allylsilanes, giving rise to a wide variety of functionalized ketones, some of which are shown in Scheme 13. The stability of a sulfone group under conditions required for acylation has potential for the formation of dienones, as demonstrated in the synthesis of ( )- and (Z)-tagetones (11) shown in Scheme 13. ... 

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