Total Synthesis of (±)-Nudenoic Acid

Copper-Catalyzed Oxidation of Alkenes and Heterocycles

“…For cyclohexene (1), 83% conversion with 64% selectivity for cyclohex-2-en-1one (77) and 29% for cyclohex-2-en-1-ol (78) was obtained. In the case of the α-pinene (86), 48% conversion led to verbenone (87) and verbenol (88) as major compounds (Scheme 31).…”

“…recovered and reused several times without loss of activity. The oxidation was carried out using H 2 O 2 as the oxidant at 70 °C for 5 hours, producing cyclohex-2-en-1-one (77) and cyclohex-2-en-1-ol (78) or verbenone (87) and verbenol (88) as the major products, respectively (Scheme 33).…”

“…Ho and Su reported the total synthesis of the sesquiterpene (±)-nudenoic acid (116), a tricyclic sesquiterpene isolated from the liverwort Mylia nuda. 88 The introduction of a carbonyl group into the allylic position of the double bond in the octalin system 114 was carried out using CuI as the catalyst and TBHP as the oxidant, in acetonitrile at 50 °C for 20 hours. The obtained enone tosylate 115 (73%) proved to be unstable, thus it was necessary to purify it at ice temperature (Scheme 41).…”

Syntheses and Applications of Functionalized Bicyclo[3.2.1]octanes: Thirteen Years of Progress

“…106 In related examples, Parker, Jr., et al reported the preparation of compounds 186a,b by intramolecular alkylation of the fluorides 185a,b in the presence of lithium chloride, presumably via the corresponding chloride. 107 Finally, two recent formal syntheses of (−)-platensimycin have been reported using similar alkylative dearomatization reactions for the construction of the tetracyclic core of the natural product.…”

Access to Enantiomerically Pure Intermediates for (−)-Geosmin Synthesis Starting from (4aS,5S)-4,4a,5,6,7,8-Hexahydro-5-hydroxy-4a-methyl-naphthalen-2(3H)-one

“…The improved yield and reproducibility of the cyclopropanation step with diethylzinc are emphasized as the key reaction. Moreover, products 2a and 3a have importance in that they can be further transformed to such sesquiterpenes as nudenoic acid 14) and others with the eudesmane skeleton.…”