Chiral Synthons from the Iridoid Glucoside Antirrhinoside − Synthesis of a Carbocyclic Homonucleoside Analogue

Abstract

The synthetic modification of the natural cyclopentanoid monoterpene glucoside antirrhinoside is reported. Some stereoselective modifications have been performed on the bicyclic iridoidic ring, resulting in opening of the dihydropyran ring. A series of chiral synthons having a highly oxygenated

Toward the Total Synthesis of Ryanodol via Oxidative Alkyne–1,3-Diketone Annulation: Construction of a Ryanoid Tetracycle

“…6 This molecular transformation presumably begins by lactone hydrolysis followed by regioselective epoxide opening in a stereoelectronically favored 6-exo manner. While both electrophilic sites of the epoxide may participate in a 6-exo ring opening process, 18 two factors may play a significant role in controlling the regioselectivity for this reaction: (1) nucleophilic addition at C12 would result in a highly strained trans -fused bicyclo[3.3.0]octane motif, 19 and (2) the C11 position is activated by the neighboring alkene. 20 While those not familiar with previous studies to prepare ryanadol may be disappointed by the observation that both 17 and 18 are produced in this two-step process, the propensity for the bridging lactone to participate in translactonization chemistry between the C11 and C3 hydroxy groups is well understood.…”

Toward the Total Synthesis of Ryanodol via Oxidative Alkyne–1,3-Diketone Annulation: Construction of a Ryanoid Tetracycle

“…6 This molecular transformation presumably begins by lactone hydrolysis followed by regioselective epoxide opening in a stereoelectronically favored 6-exo manner. While both electrophilic sites of the epoxide may participate in a 6-exo ring opening process, 18 two factors may play a significant role in controlling the regioselectivity for this reaction: (1) nucleophilic addition at C12 would result in a highly strained trans -fused bicyclo[3.3.0]octane motif, 19 and (2) the C11 position is activated by the neighboring alkene. 20 While those not familiar with previous studies to prepare ryanadol may be disappointed by the observation that both 17 and 18 are produced in this two-step process, the propensity for the bridging lactone to participate in translactonization chemistry between the C11 and C3 hydroxy groups is well understood.…”

Centrifugal partition chromatography: an efficient tool to access highly polar and unstable synthetic compounds on a large scale

“…Elemental analysis of aucubin puried by chromatography: anal. calcd for C 15 H 22 O 9 $H 2 O: C,49.45;H,6.64;O,43.91. Found: C,49.35;H,6.78;O 44.11 ,49.45;H,6.64;O,43.91.…”

Iodine-Catalyzed Etherification of Morroniside

“…The importance of these compounds has been demonstrated in various synthetic approaches. [1][2][3][4][5][6][7][8][9][10] Recent synthetic applications have resulted into conversion of aucibin to aminoside antibiotic analogues. 11) Morroniside (1) has been found to have some applications in pharmacology as well as in cosmetics.…”

Toward the Total Synthesis of Ryanodol via Oxidative Alkyne–1,3-Diketone Annulation: Construction of a Ryanoid Tetracycle

“…6 This molecular transformation presumably begins by lactone hydrolysis followed by regioselective epoxide opening in a stereoelectronically favored 6-exo manner. While both electrophilic sites of the epoxide may participate in a 6-exo ring opening process, 18 two factors may play a significant role in controlling the regioselectivity for this reaction: (1) nucleophilic addition at C12 would result in a highly strained trans -fused bicyclo[3.3.0]octane motif, 19 and (2) the C11 position is activated by the neighboring alkene. 20 While those not familiar with previous studies to prepare ryanadol may be disappointed by the observation that both 17 and 18 are produced in this two-step process, the propensity for the bridging lactone to participate in translactonization chemistry between the C11 and C3 hydroxy groups is well understood.…”

Centrifugal partition chromatography: an efficient tool to access highly polar and unstable synthetic compounds on a large scale

“…Elemental analysis of aucubin puried by chromatography: anal. calcd for C 15 H 22 O 9 $H 2 O: C,49.45;H,6.64;O,43.91. Found: C,49.35;H,6.78;O 44.11 ,49.45;H,6.64;O,43.91.…”

Iodine-Catalyzed Etherification of Morroniside

“…The importance of these compounds has been demonstrated in various synthetic approaches. [1][2][3][4][5][6][7][8][9][10] Recent synthetic applications have resulted into conversion of aucibin to aminoside antibiotic analogues. 11) Morroniside (1) has been found to have some applications in pharmacology as well as in cosmetics.…”

Toward the Total Synthesis of Ryanodol via Oxidative Alkyne–1,3-Diketone Annulation: Construction of a Ryanoid Tetracycle

“…6 This molecular transformation presumably begins by lactone hydrolysis followed by regioselective epoxide opening in a stereoelectronically favored 6-exo manner. While both electrophilic sites of the epoxide may participate in a 6-exo ring opening process, 18 two factors may play a significant role in controlling the regioselectivity for this reaction: (1) nucleophilic addition at C12 would result in a highly strained trans -fused bicyclo[3.3.0]octane motif, 19 and (2) the C11 position is activated by the neighboring alkene. 20 While those not familiar with previous studies to prepare ryanadol may be disappointed by the observation that both 17 and 18 are produced in this two-step process, the propensity for the bridging lactone to participate in translactonization chemistry between the C11 and C3 hydroxy groups is well understood.…”

Centrifugal partition chromatography: an efficient tool to access highly polar and unstable synthetic compounds on a large scale

“…Elemental analysis of aucubin puried by chromatography: anal. calcd for C 15 H 22 O 9 $H 2 O: C,49.45;H,6.64;O,43.91. Found: C,49.35;H,6.78;O 44.11 ,49.45;H,6.64;O,43.91.…”

Iodine-Catalyzed Etherification of Morroniside

“…The importance of these compounds has been demonstrated in various synthetic approaches. [1][2][3][4][5][6][7][8][9][10] Recent synthetic applications have resulted into conversion of aucibin to aminoside antibiotic analogues. 11) Morroniside (1) has been found to have some applications in pharmacology as well as in cosmetics.…”