6819-38-1

Upstream product

• 121424-59-7 6,10-dimethyl-9-undecene-2,6-diol 
• 3879-26-3 (Z)-nerylacetone 
• 15146-94-8 5-chloro-2-pentanol 
• 110-93-0 6-Methyl-hept-5-en-2-on 

Downstream Products

• 39721-65-8 (R)-(+)-α-dihydroionone 
• 3239-37-0 (E)-6,10-dimethylundeca-5,9-dien-2-yl acetate 

Relevant academic research and scientific papers

Asymmetric Cation-Olefin Monocyclization by Engineered Squalene–Hopene Cyclases

Squalene–hopene cyclases (SHCs) have great potential for the industrial synthesis of enantiopure cyclic terpenoids. A limitation of SHC catalysis has been the enzymes’ strict (S)-enantioselectivity at the stereocenter formed after the first cyclization step. To gain enantio-complementary access to valuable monocyclic terpenoids, an SHC-wild-type library including 18 novel homologs was set up. A previously not described SHC (AciSHC) was found to synthesize small amounts of monocyclic (R)-γ-dihydroionone from (E/Z)-geranylacetone. Using enzyme and process optimization, the conversion to the desired product was increased to 79 %. Notably, analyzed AciSHC variants could finely differentiate between the geometric geranylacetone isomers: While the (Z)-isomer yielded the desired monocyclic (R)-γ-dihydroionone (>99 % ee), the (E)-isomer was converted to the (S,S)-bicyclic ether (>95 % ee). Applying the knowledge gained from the observed stereodivergent and enantioselective transformations to an additional SHC-substrate pair, access to the complementary (S)-γ-dihydroionone (>99.9 % ee) could be obtained.

Chlorosulfonic acid as a convenient electrophilic olefin cyclization agent

Among several sulfonic acids studied (MeSO3H, p-TsOH, H2SO4, ClSO3H, FSO3H), the scarcely used chlorosulfonic acid showed to be an efficient agent for electrophilic olefin cyclizations with internal nucleophilic termination, in a similar manner that is well-established with fluorosulfonic acid. Its availability, lower price and relatively lesser handling problems makes ClSO3H an advantageous cyclizing agent particularly for high-scale applications. The stereochemical outcome of these cyclizations has been rationalized.

BIOTRANSFORMATIONS OF ACYCLIC TERPENOIDS; (+/-)-CIS-NEROLIDOL AND NERYLACETONE, BY PLANT PATHOGENIC FUNGUS, GLOMERELLA CINGULATA

Microbial transformations of (+/-)-cis-nerolidol and nerylacetone were investigated using the plant pathogenic fungus, Glomerella cingulata.Both (+/-)-cis-nerolidol and nerylacetone were mainly oxidized at the remote double bond. (+/-)-cis-nerolidol was transformed into (Z)-3,7,11-trimethyl-1,6-dodecadien-3,10,11-triol while nerylacetone was transformed into (Z)-9,10-dihydroxy-6,10-dimethyl-5-undecen-2-one as the major metabolite.In addition, the biotransformation of nerylacetone resulted in hydration at the remote double bond and reduction of the carbonyl group and produced (Z)-6,10-dimethyl-5,9-undecadien-2-ol, (Z)-10-hydroxy-6,10-dimethyl-5-undecen-2-one and (Z)-6,10-dimethyl-5-undecen-2,9,10-triol.The structures of the metabolic products were determined by spectroscopic data. - Keywords: Glomerella cingulata; biotransformation; microbial transformation; plant pathogenic fungus; (+/-)-cis-nerolidol; nerylacetone.