56881-45-9

Upstream product

• 1178893-40-7 (+)-4-hydroxy-γ-cyclogeraniol 
• 488-93-7 3-Furoic acid 
• 1178893-44-1 C₁₄H₂₂O₄ 
• 14497-29-1 3-(chloromethyl)furan 
• 85867-72-7 2-(2-Furan-3-yl-ethyl)-1,3,3-trimethyl-7-oxa-bicyclo[4.1.0]heptane 
• 82043-26-3 (+/-)-pallescensin 1 
• 85867-66-9 3-<2-(2-furyl)ethyl>-4,4-dimethyl-2-methylenecyclohexanol 

Relevant academic research and scientific papers

A general strategy for the stereoselective synthesis of the furanosesquiterpenes structurally related to pallescensins 1-2

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.

Furanosesquiterpenoids: Total Synthesis of Pallescensins 2, F, and G

Oxidation of the synthetic pallescensin 1 with m-chloroperbenzoic acid, follwed by treatment of the resulting epoxide with lithium diethylamide, afforded 3--4,4-dimethyl-2-methylenecyclohexanol (6).The alcohol 6 was dehydrated with refluxing hexamethylphosphoric triamide to give pallescensin 2.Oxidation of 6 with pyridinium chlorochromate, followed by intramolecular cyclization with 85percent phosphoric acid, afforded 5,5a,6,7,8,9,9a,10-octahydro-6,6-dimethyl-4H-benzocycloheptafuran-9-one.This was converted into the corresponding α,β-unsaturated ketone (10) via an α-phenylseleno ketone.Reduction of 10 with lithium aluminium hydride, followed by dehydration with hexamethylphosphoric triamide at 200-210 deg C, afforded pallescensin G, which was further isomerized to pallescensin F.