38301-70-1

Upstream product

• 139932-54-0 ethyl 3-(β-phenylethyl)-2,2-dimethyl-4-oxocyclohexancarboxylate 
• 139932-51-7 ethyl 3-(β-phenylethyl)-2,2-dimethyl-4-methylenecyclohexancarboxylate 
• 139932-55-1 (4aR,10aR)-1,1,4a-Trimethyl-1,2,3,4,4a,9,10,10a-octahydro-phenanthrene-2-carboxylic acid ethyl ester 
• 139932-57-3 (+/-)-3α-O-acetylpodocarpa-8,11,13-triene 
• 139932-56-2 (+/-)-podocarpa-8,11,13-triene-3-carboxylic acid 
• 103-63-9 1-phenyl-2-bromoethane 
• 20653-52-5 ethyl 3-(β-phenylethyl)-2-methyl-4-oxocyclohex-2-enecarboxylate 
• 487-51-4 4-carbethoxy-3-methyl-2-cyclohexen-1-one 

Downstream Products

• 38301-73-4 1,1,4a-trimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-2β-ol 

Relevant academic research and scientific papers

An unexpected (3 → 2)-hydride shift in phyllocladane (=13β-kaurane) diterpenoids and in related trimethyl-substituted Bi- and tricyclic compounds

The conversion of 2α,3α-dioxy-substituted phyllocladane derivatives into the corresponding 3-ketone proceeds in an unexpected manner: Depending on the reaction conditions, the corresponding 3β-hydroxy-substituted compound is formed almost quantitatively,

An expeditious stereoselective total synthesis of (±)-podocarpa-2,8,11,13-tetraene and 3-oxygenated (±)-podocarpa-8,11,13-trienes by acid-catalyzed cyclialkylation route

An expeditious total synthesis of (±)-podocarpa-2,8,11,13-tetraene (4) and the epimeric (±)-3-hydroxypodocarpa-8,11,13-trienes 5 and 6 by a stereoselective cyclialkylation route is described.

Synthetic Studies in Diterpene Series. Part X. A Synthesis of 2-Oxygenated (+/-)-Podocarpa-8,11,13-triene by Transposition of Ketonic Function

Carbanions generated in situ through de-ethoxycarbonylation of ethyl 2-cyano-3,3-dimethyl-5-oxohexanoate (11) and ethyl phenethylcyanoacetate (7) by heating with lithium chloride in hexamethylphosphorus triamide according to Krapcho have been submitted respectively to alkylation reaction with phenethyl bromide and to Michael addition with 4-methylpent-3-en-2-one with a view to utilising the resultant 5-cyano-4,4-dimethyl-7-phenylheptan-2-one (10) for a convenient synthesis of 2-oxopodocarpa-8,11,13-trienes (6).The yields of the reactions are, however, poor (15-20percent), presumably due to adverse steric effect of the geminal methyl groups in the reactants.Use of sodium hydride under phase transfer catalysis considerably improves the yield of alkylation reaction (with the keto group in 11 protected by cyclic acetal formation) and the product (14) undergoes de-ethoxycarbonylation; but the resultant nitrile (15) is found to be resistant to hydrolysis leading to an impasse. 2-Oxopodocarpa-8,11,13-triene (20) is finally synthesised from the easily accessible 3-oxo-derivative (18) by transposition of the ketonic function through a two step process, namely oxidation with molecular oxygen in presence of potassium t-butoxide to 2,3-dioxo-derivative and its subsequent reduction with boiling hydriodic acid.The ketone (20) on treatment with lithium aluminium hydride affords 2β(axial) and 2α(equatorial) alcohols in a 60 : 40 ratio.