6090-04-6

Upstream product

• 89-82-7 pulegone 
• 80995-97-7 (-)-(4R)-isopiperitenone 
• 89-79-2 (S)-2-Isopropenyl-5-methyl-cyclohexanol 
• 7540-51-4 (S)-3,7-dimethyl-6-octen-1-ol 
• 5949-05-3 (S)-Citronellal 

Downstream Products

• 144541-38-8 <1R-(1α,2α,5α)>-5-Methyl-2-(1-methylethenyl)cyclohexanol 
• 7786-67-6 isopulegol 
• 89-82-7 pulegone 
• 10458-14-7 (2R,5S)-menthone 
• 1196-31-2 (1R,4R)-(+)-isomenthone 
• 3391-90-0 (S)-(-)-pulegone 
• 80183-38-6 (6S)-3,6-dimethyl-4,5,6,7-tetrahydrobenzo[b]furan 
• 57707-92-3 (2R/S,5S)-5-Methyl-2-(1-methyl-1-phenylethyl)cyclohexanone 
• 122517-58-2 (-)-(1R,2S,5S)-5-Methyl-2-(1-methyl-1-phenylethyl)cyclohexanol 
• 57707-91-2 (1S,2R,5S)-8-(+)-phenylmenthol 
• 4581-56-0 (+)-isoisopulegone semicarbazone 

Relevant academic research and scientific papers

Chemoenzymatic Synthesis of the Intermediates in the Peppermint Monoterpenoid Biosynthetic Pathway

A chemoenzymatic approach providing access to all four intermediates in the peppermint biosynthetic pathway between limonene and menthone/isomenthone, including noncommercially available intermediates (-)-trans-isopiperitenol (2), (-)-isopiperitenone (3), and (+)-cis-isopulegone (4), is described. Oxidation of (+)-isopulegol (13) followed by enolate selenation and oxidative elimination steps provides (-)-isopiperitenone (3). A chemical reduction and separation route from (3) provides both native (-)-trans-isopiperitenol (2) and isomer (-)-cis-isopiperitenol (18), while enzymatic conjugate reduction of (-)-isopiperitenone (3) with IPR [(-)-isopiperitenone reductase)] provides (+)-cis-isopulegone (4). This undergoes facile base-mediated chemical epimerization to (+)-pulegone (5), which is subsequently shown to be a substrate for NtDBR (Nicotiana tabacum double-bond reductase) to afford (-)-menthone (7) and (+)-isomenthone (8).

Biosynthesis of menthofuran in Mentha x piperita: Stereoselective and mechanistic studies

Mentha x piperita shoot tips and first leaf pair were fed with aqueous solutions of [2H2]- and [2H2]/[18O]-labeled pulegone. The essential oil was analyzed by solid phase microextraction and enantioselective multidimensional gas chromatography/mass spectrometry. After feeding experiments with labeled pulegone racemate, both labeled (S)-menthofuran and (R)-menthofuran were detectable simultaneously together with genuine (R)- menthofuran. It could be shown that both labeled pulegone enantiomers are converted by Mentha x piperita to the corresponding labeled menthofuran enantiomers, favoring the labeled analogue of the nongenuine (S)-pulegone. The oxygen in menthofuran is introduced by enzymatic oxidation of pulegone, as concluded from feeding experiments with mixed labeled [2H2]/[18O]pulegone.

Large-Scale Preparation of Pure (+)-(1S,2R,5S)-5-Methyl-2-(1-methyl-1-phenylethyl)cyclohexanol

A procedure is described for the preparation of (S)-(-)pulegone, (-)-1, starting from (S)-(-)citronellol, (-)-6, in a preparative scale.Compound (-)-1 can easily be converted into (+)-(1S,2R,5S)-5-methyl-2-(1-methyl-1-phenylethyl)cyclohexanol: (+)-2 by a procedure described in literature, which was simplified essentially.Now (+)-2 is accessible in larger amounts and thus is available as an efficient chiral auxiliary in stoichiometric asymmetric syntheses.