Highly Exo-Selective Epoxidation and Hydroxylation of Triquinacene and Its Derivatives:  all-exo-Hexahydroxytriquinane

Abstract

Epoxidation of triquinacene 3 with dimethyldioxirane proceeded with a high degree of exo-face selectivity to give a quantitative yield of a 1:1.5 mixture of all-exo-4a and endo,exo,exo-triepoxytriquinane 4b. Subsequent lithium aluminum hydride reduction of the all-exo-triepoxide 4a gave all-exo-2,5,8-5a and all-exo-2,5,9-trihydroxytriquinane 5b, respectively. The straightforward 3-fold dihydroxylation of triquinacene 3 led exclusively to the all-exo-hexahydroxytriquinane 8 in one step. X-ray crystal structure analyses confirmed the configuration of the triepoxide 4b and the hexaacetate 9 of the hexol 8.

Three-Dimensional Hydrocarbon Cores Based on Multiply Fused Cyclopentane and Indane Units: Centropolyindanes

“…Numerous efforts were invested to pursue this idea, including an approach by multiple aldol addition of the C 3 -symmetrical, and thus chiral, perhydroquinacenetrione 21 by Serratosa et al . Besides the discussion on the long-assumed homoconjugative interaction between the π bonds of 18 , − the generation and properties of the triquinacene-10-yl cation was put forward. ,, Many bridgehead-functionalized derivatives of triquinacene, such as 19 , − a few centro -substituted ones, e.g., 20 , , and peripherally functionalized ones, e.g., the interesting all- exo -hexaol 22 , have been described and studied, mainly with respect to their reactivity toward complexation with metal carbonyl fragments, reduction, and elimination. The deprotonation/dehydrogenation pathways of 18 and some derivatives by use of superbases have also been studied in great detail, ,− and the existence of neutral acepentalene ( 23 ), having remained elusive in condensed media, was demonstrated in the gas phase .…”

Design of water-soluble, thiol-reactive polymers of controlled molecular weight: a novel multivalent scaffold

“…To restore water solubility, we carried out the dihydroxylation of the double bonds in the polymer backbone. The reaction of the polymer with NMO and a catalytic amount of potassium osmate was performed in a 1:1:1 solution of methanol, acetone, and water [36], and was followed by dialysis against deionized water for polymer purification. Figure 2(a) shows the 1 H NMR spectra of the resulting polymer.…”

“…1 ml methanol and 1 ml acetone were added to the chloroacetylated polymer (77 mg) [36]. The mixture was placed in an ice bath and an aqueous solution of NMO was added (41 mg), followed by an aqueous solution of potassium osmate dihydrate (0.59 mg).…”

Stereoselective Epoxidation of Cyclohexa-Anellated Triquinacenes with Iodine/Silver(I) Oxide As Compared to m-Chloroperbenzoic Acid1

“…Triquinacenes 1 and 2 , which are readily obtained by Benkeser reduction and by Birch reduction, respectively, of 10-methyltribenzotriquinacene, were considered particularly interesting since three-fold epoxidation at the convex side of these bowl-shaped cyclic 1,4,7-trienes should enhance the convexity of the polycyclic framework and possibly open a synthetic access to novel cage structures . In contrast to cyclonona-1,4,7-triene, which undergoes stereoselective epoxidation with m -chloroperbenzoic acid, , epoxidation of triquinacenes constituting completely rigid all - cis -1,4,7-nonatriene derivatives has not been reported previously 1 …”