124867-96-5

Upstream product

• 497-03-0 2-methylbut-2-enal 
• 99181-10-9 2-Methyl-5-(1-methyl-acetonyl)-cyclopentanon 
• 124986-85-2 (5SR,6RS)-2,6-dimethylbicyclo<3.3.0>oct-1-en-3-one 
• 124867-91-0 (3aR,4S,6aR)-6a-[2-(5,5-Dimethyl-[1,3]dioxan-2-yl)-1-methyl-propyl]-1,4-dimethyl-hexahydro-pentalen-2-one 
• 124867-90-9 2-(2-iodo-1-methylpropyl)-5,5-dimethyl-1,3-dioxane 
• 1120-72-5 2-Methylcyclopentanone 
• 937-63-3 p-Tolyl chlorothionoformate 
• 124867-92-1 (1SR,5SR,8RS,9RS)-4-hydroxy-2,3,5,9-tetramethyltricyclo<6.3.0.0^1.5>undecan-6-one 

Downstream Products

• 106-44-5 p-cresol 
• 124867-93-2 rac-silphiperfol-5-en-3-one 

Relevant academic research and scientific papers

Terpenes and Terpene Derivatives, XXIX Synthesis and Olfactive Properties of (-)- and rac-Silphiperfol-5-en-3-ol and of Some Tris-nor Derivatives

The new sesquiterpene alcohols silphiperfol-5-en-3-ol and the corresponding 7-epi compound (+)-1b, important constituents of the essential oil of Artemisia laciniata have been synthesized in 13 steps by starting from (R)-(+)-pulegone (6) in an overall yield of 8percent.The key reaction is the copper-catalyzed 1,4-Grignard addition of the iodo acetal 34 to the enone (+)-4 in the presence of TMSCl and TMEDA to give the silyl ether 38.Hydrolysis with spontaneous aldol cyclization and dehydration leads to the silphiperfolenones (+)-2a,b which are separable by flash chromatgraphy.The reduction with L-selectrideR gives the alcohols (-)-1a and (+)-1b which are identical in all physical properties with the isolated natural compound.With LiAlH4 the diastereoisomers 42a,b are formed.Olfactive evaluation of the isomers (-)-1a and (+)-1b has shown that the odor of the naturally occuring mixture of 1a,b with the descriptors woody, ambergris, slightly camphoraceous is correctly assigned. (-)-1a represents the more woody and camphoraceous, (+)-1b the more animal facette of ambergris.The odor of rac-1a,b, of the diasteroisomers 42a,b and of the ketones (+)-2a,b is also described as well as that of the tris-nor-silphiperfolene derivatives 29-31. Key Words: Artemisia laciniata / Sesquiterpene alcohols, tricyclic / Structure-odor correlation / (R)-(+)-Pulegone / 1,4-Grignard reaction

TOTAL SYNTHESIS OF (+/-)-SILPHIPERFOL-5-EN-3-OL

Silphiperfol-5-en-3-ol (1) has been synthesized in five steps starting with enone 4 in an overall yield of 30percent.Key step is a TMSCl assisted 1,4-addition of the Grignard reagent of acetal 5 to 4.