Synthesis of the C5–C30 fragment of cyclodidemniserinol trisulfate via I2-mediated deprotection and ring closure tandem reaction

Exploring Acetylene Chemistry: A Transition Metal-Free Route to Dienyl 6,8-Dioxabicyclo[3.2.1]octanes from Ketones and Acetylenes

“…13 C{ 1 H} NMR (C 6 D 6 ): δ 208.5 (CO), 149.3 (C6), 141.0, 140.0, 137.9, 137. 5,137.3,136.3,132.9,132.8,129.4,129.2,128.7,127.0,127.0,126.9,126.7,124.6 (24C,Ph), 124.9 (C β ), 122.6 (C γ ), 104.6 (C5), 87.3 (C2), 40.6 (C α ), 39.8 (C3), 25.2 (C4), 20.9, 20.9, 20.7 (3C, Me).…”

“…The bridgehead bicyclic acetal architectures 6,8-dioxabicyclo[3.2.1]­octanes (commonly abbreviated as 6,8-DOBCOs), represent a naturally abundant scaffold met in the molecules of insect pheromones (frontalin, brevicomin, , multistriatin ,, ), mammal hormones, and marine toxins . Some 6,8-DOBCOs are found to possess anticancer and antiviral activity.…”

“…The bridgehead bicyclic acetal architectures 6,8dioxabicyclo [3.2.1]octanes (commonly abbreviated as 6,8-DOBCOs), represent a naturally abundant scaffold met in the molecules of insect pheromones (frontalin, 1 brevicomin, 1a,2 multistriatin 1a,2b,3 ), mammal hormones, 4 and marine toxins. 5 Some 6,8-DOBCOs are found to possess anticancer 6 and antiviral 7 activity. Therefore, the interest in this class of compounds keeps steadily growing, and novel approaches to their synthesis warranting structural diversity are in demand.…”

An Easy Access to Sulfur Derivatives of 6,8-Dioxabicyclo[3.2.1]octanes, Naturally Abundant Scaffolds

“…Indeed, these unique heterocyclic structures are frequently encountered in numerous natural products, for example insect pheromones (frontalin, 3 brevicomin, 4,5 multistriatin 5,6 ), mammalian hormones 7 and marine toxins. 8 Thus, it is no wonder that this motif as a structural counterpart of a number of biologically active compounds has ignited an ever-growing interest from experts in organic synthesis and biochemistry. This has resulted in elaboration of various synthetic approaches which differ in their efficiency, being mostly transition-metal-catalyzed and multistep.…”

ChemInform Abstract: Chemoenzymatic Synthesis of Pleiogenone A: An Antiproliferative Trihydroxyalkylcyclohexenone Isolated from Pleiogynium timorense.

“…From previous synthetic ventures with ipso-diol 6 we had learnedt hat the hydroxymethyl functionality is severely hindered and unresponsive in av ariety of reactions. [15] Alcohol 12 wasc onverted to ar ather labile aldehyde 15 and aW ittig reactiono ft he phosphonium salt 16 (synthesizedf rom 1,7-heptanediol as has been reported for similarW ittig reagents) [16] furnished the triene 17 in 40 %y ield over the two steps, reflecting the instability of the aldehyde.T he advantage of introducing the side chain in portions will ultimately allow for the synthesis of congeners 2 and 3 from the same intermediate. The [2 + 4] cycloaddition of 17 with singlet oxygen produced the endo-peroxide 18 in good yields.…”