116296-76-5

Upstream product

• 57069-86-0 7,8-dihydro-3,4-dehydro-β-ionol 
• 36431-72-8 2,6,10,10-tetramethyl-1-oxaspiro[4.5]dec-6-ene 
• 66965-88-6 (2R*,5R*)-2,6,10,10-Tetramethyl-1-oxaspiro<4.5>dec-6-en 
• 39763-31-0 (±)-(3E)-4-[1,4-dihydroxy-2,6,6-trimethylcyclohex-2-en-1-yl]but-3-en-2-one 
• 78830-89-4 6,6-dimethyl-2-methylene-1-(3-oxo-1-butenyl)-3-cyclohexen-1-ol 
• 14398-35-7 (3E)-4-(2,6,6-trimethylcyclohexa-1,3-dien-1-yl)but-3-en-2-one 
• 78830-92-9 (6RS,9SR)-1-(3-hydroxybutyl)-6,6-dimethyl-2-methylene-3-cyclohexen-1-ol 
• 78830-90-7 6,6-dimethyl-2-methylene-1-(3-oxobutyl)-3-cyclohexen-1-ol 

Relevant academic research and scientific papers

Syntheses of theaspirone and vitispirane via palladium(II)-catalyzed oxaspirocyclization

Total syntheses of theaspirone (A and B) and vitispirane (A and B) are described. The key step in the syntheses is the palladium(II)-catalyzed intramolecular oxaspirocyclization of diene alcohol 4 to either vitispirane or the allylic alcohol 9. The outcome of the oxaspirocyclization is very much dependent on the solvent employed. In water-acetic acid (4:1) a 1:1 mixture of the diastereomeric alcohols 9A and 9B was exclusively formed. In water with 8 equiv of a strong non-nucleophilic acid, vitispiranes A and B (1:1) were obtained. An alternative procedure to obtain vitispirane with the use of LiCl and K2CO3 is described. In the latter reaction vitispirane B is formed preferentially. This result is explained by an equilibrium between the two possible π-allyl complexes 5A and 5B, the kinetically favored 5B being transformed into vitispirane 3B before isomerization to 5A occurs.

Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus - Conversion of selected spirocyclic terpenoids and computational analysis

Allylic oxidations of olefins to enones allow the efficient synthesis of value-added products from simple olefinic precursors like terpenes or terpenoids. Biocatalytic variants have a large potential for industrial applications, particularly in the pharmaceutical and food industry. Herein we report efficient biocatalytic allylic oxidations of spirocyclic terpenoids by a lyophilisate of the edible fungus Pleurotus sapidus. This ''mushroom catalysis'' is operationally simple and allows the conversion of various unsaturated spirocyclic terpenoids. A number of new spirocyclic enones have thus been obtained with good regio- and chemoselectivity and chiral separation protocols for enantiomeric mixtures have been developed. The oxidations follow a radical mechanism and the regioselectivity of the reaction is mainly determined by bond-dissociation energies of the available allylic CH-bonds and steric accessibility of the oxidation site.

A New Route to Vitispiranes

Diastereoisomeric vitispiranes have been synthesized from 2,6,6-trimethyl-1-(3-oxo-1-butenyl)-1,3-cyclohexadiene by five-step reactions including photooxygenation.