5502-76-1

Upstream product

• 5502-99-8 p-menth-8(10)-en-9-ol 
• 6252-33-1 4-isopropenyl-1-methylcyclohexane 
• 74410-10-9 (3R,4S,8S)-3,9-epoxy-p-menth-1-ene 
• 208336-26-9 (4S)-p-mentha-1,5-dien-9-ol 
• 118015-24-0 (-)-(3S,4R,8S)-3,9-epoxy-1-p-menthene 
• 118015-25-1 (3R,3aR,7aS)-3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran 
• 1340481-23-3 (4S,8R)-p-mentha-1,5-dien-9-ol 
• 1340481-21-1 (4S,8S)-p-mentha-1,5-dien-9-ol 
• 1340481-27-7 (4S,8S)-p-mentha-1,5-dien-9-yl 3,5-dinitrobenzoate 
• 1340481-29-9 (4S,8R)-p-mentha-1,5-dien-9-yl 3,5-dinitrobenzoate 
• 5989-27-5 D-limonene 
• 35650-70-5 8,9-epoxy-p-menthane 

Relevant academic research and scientific papers

Chemoenzymatic preparation of the p-menth-1,5-dien-9-ol stereoisomers and their use in the enantiospecific synthesis of natural p-menthane monoterpenes

A study on the preparation and synthetic exploitation of the isomeric forms of p-menth-1,5-dien-9-ol is reported. The latter alcohols were prepared in high enantiomeric purity from the easily available enantiomers of carvone. Thus, a chemoenzymatic procedure based on lipase-mediated acetylation, allowed the separation of their diastereoisomeric forms. Moreover, the purity of the chiral building blocks obtained was improved by fractional crystallisation of their 3,5-dinitrobenzoyl derivatives. A number of synthetic applications have also been described. The stereospecific cyclisation of the isomerically pure dienic alcohols gave the isomeric forms of the terpenes dill and epi-dill ether, which were hydrogenated diastereoselectively to the corresponding (1R)- or (1S)-derivatives depending on the catalyst used. The oxidation of the latter ethers turned out to be stereoselective, affording either the corresponding p-menthan-9-oic lactone or the keto-acid derivatives depending on the starting isomer used.

Regioselective semihydrogenation of dienes

A one-pot, three-step strategy for the regioselective semihydrogenation of dienes is described. This procedure uses 9-BBN-H as a temporary protective group for alkenes. Yields range from 55% to 95%, and the reaction is tolerant of a variety of common functional groups. Additionally, the final elimination step of the sequence can be replaced with a peroxide-mediated alkylborane oxidation, generating regioselectively semihydrogenated product alcohols.