01327nas a2200169   4500008004100000022001400041245007100055210006500126260000900191300001600200490000700216520076900223100002200992700002601014700002201040856009501062       2021                        eng d  a0022-326300aStereoselective total synthesis of (+/-)-pleurospiroketals A and B0 aStereoselective total synthesis of pleurospiroketals A and B  cOCT   a13572-135820 v863 aA full account of our efforts toward the stereoselective total synthesis of sesquiterpenoid-derived natural products (+/-)-pleurospiroketals A and B is described. Commercially available 3-methyl-2-cyclohexenone and 2,2-dimethyloxirane were used as key building blocks, and the substrate-controlled stereoselection was exploited to access the entire stereochemistry of these natural products. Initially, a planned synthetic route involving a [6,5]-bicyclic lactone intermediate was found to be insurmountable, and the later strategy comprising OsO4-NMO-mediated dihydroxylation of 3-methyl-2-cyclohexenone, followed by Luche reduction, Eschenmoser methylenation, and Bronsted acid-induced spiroketalization steps, was ultimately identified as the reliable strategy.1 aThorat, Sagar, S.1 aKrishna, Gamidi, Rama1 aKontham, Ravindar  uhttps://library.ncl.res.in/content/stereoselective-total-synthesis-pleurospiroketals-and-b