Stereoselective synthesis of cis-p-menth-8-ene-1,7-diol, cis-p-menthane-1,7-diol, and cis-p-menthane-1,7,8-triol.
The natural products cis-p-menthane-1,7-diol (cis-IV), cis-p-menth-8-ene-1,7-diol (cis-I) and cis-p-menthane-1,7,8-triol (cis-II) are obtained starting from the corresponding cis-cyanohydrins, cis-2 and cis-7, respectively, by chemical transformation of the cyano into the hydroxymethyl group. The key step of the synthesis is the very high cis-selectivity (> or = 96 %) of the MeHNL-catalyzed HCN addition to 4-alkylcyclohexanones. From 4-isopropylcyclohexanone (1) the cyanohydrin cis-2 and from 4-(1-methylvinyl)cyclohexanone (6) the cyanohydrin cis-7 result almost quantitatively. Regioselective hydroxylation of cis-I affords the triol cis-II. X-ray crystal structure determinations of the final products confirm their cis-configuration.
Kobler
Christoph
C
Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Effenberger
Franz
F
D018360:Crystallography, X-Ray; D000081005:Cyclohexane Monoterpenes; D006856:Hydrogen Cyanide / Q000737:chemistry; D008610:Menthol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D039821:Monoterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D009570:Nitriles / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D009570:Nitriles; C430593:cyanohydrin; C079976:4-menthane-1,7,8-triol; D008610:Menthol; D006856:Hydrogen Cyanide