815581-82-9Relevant academic research and scientific papers
A general strategy for the stereoselective synthesis of the furanosesquiterpenes structurally related to pallescensins 1-2
Serra, Stefano
, (2019/05/24)
Here, we describe a general stereoselective synthesis of the marine furanosesquiterpenes structurally related to pallescensins 1-2. The stereoisomeric forms of the pallescensin 1, pallescensin 2, and dihydropallescensin 2 were obtained in high chemical and isomeric purity, whereas isomicrocionin-3 was synthesized for the first time. The sesquiterpene framework was built up by means of the coupling of the C10 cyclogeranyl moiety with the C5 3-(methylene)furan moiety. The key steps of our synthetic procedure are the stereoselective synthesis of four cyclogeraniol isomers, their conversion into the corresponding cyclogeranylsulfonylbenzene derivatives, their alkylation with 3-(chloromethyl)furan, and the final reductive cleavage of the phenylsulfonyl functional group to afford the whole sesquiterpene framework. The enantioselective synthesis of the α-, 3,4-dehydro-γ- and γ-cyclogeraniol isomers was performed using both a lipase-mediated resolution procedure and different regioselective chemical transformations.
A simple and efficient highly enantioselective synthesis of α-ionone and α-damascone
Bovolenta, Marcella,Castronovo, Francesca,Vadala, Alessandro,Zanoni, Giuseppe,Vidari, Giovanni
, p. 8959 - 8962 (2007/10/03)
An efficient highly enantioselective (ee ≥99%) synthesis of α-ionone and α-damascone is described. Both enantiomers of title compounds were synthesized through two straightforward pathways diverging from enantiopure (R)- or (S)-α-cyclogeraniol. These versatile building blocks were obtained by regioselective ZrCl4-promoted biomimetic cyclization of (6S)- or (6E)-(Z)-6,7-epoxygeraniol, respectively, followed by deoxygenation of the so formed secondary alcohol. The chiral information was encoded by a highly regioselecive Sharpless asymmetric dihydroxylation of inexpensive geranyl acetate.
