Determination of the absolute structure of albaconol

Drimane-Related Merosesquiterpenoids, a Promising Library of Metabolites for Drug Development

“…Based on the cyclization between sesquiterpenoid and 3,5-dimethylorsellinic acid (DMOA) units, as well as the rearrangement of DMOA, the type of tetraketide-MSRDs can be further classified into five subgroups (SG I-V), namely citreohybridones , terretonins (148)(149)(150)(151)(152)(153)(154)(155)(156), andibenins (157)(158)(159)(160)(161)(162)(163), autins , and others (194)(195)(196)(197)(198)(199). Isotope labeling experiments revealed that they were all formed through the alkylation of DMOA by FPP as a key step [87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102].…”

“…Tauranin (201) was obtained from the mycelium of O. aurantia [9], and its derivatives 4′-hydroxymethylcyclozonarone (202), 3-ketotauranin (203), 3α-hydroxytauranin (204), 12-hydroxytauranin (205), and phyllospinarone (206) were isolated from Phyllosticta spinarum, an endophyte in Platycladus orientalis [150]. By comparison of its optical rotation with that of synthetic (-)-albaconol, the absolute configuration of natural albaconol (207) from the fresh fruiting bodies of Albatrellus confluens [151] was determined as 207 [152]. Hydroquinone (208) was isolated from a deep sea sediment derived fungus, Phialocephala sp.…”

Natural sesquiterpenoids

“…41 The absolute configuration of albaconol has been determined as 69 by synthesis of its enantiomer from (8aR)-albicanol. 61 (À)-Ambrox Ò has been obtained by chemical degradation of the triterpene oleanolic acid. 62 Both enantiomers of the sesquiterpene FF8181-A have been synthesized permitting the determination of the absolute configuration of the natural compound as 70.…”

Recent Advances in the Syntheses of Decalin Type Natural Products

“…Structure of 115 was determined by spectral analysis but the absolute structure of 115 was not determined yet. We report the first synthesis of (8aR)-albaconol (115) from (8aR)-albicanol (64) and determination of the absolute structure of natural albaconol (115) based on chiral synthesis (8aR)-115 as shown in Scheme 15 43. Dess-Martin oxidation of (8aR)-64 gave a (8aR)-albicanal (87) in 92% yield, which was treated with 3,5-bis-(methoxymethyloxy)toluene in the presence of n-BuLi to afford a diastereomeric mixture of (10R)-110.…”