Synthesis of the ABC fragment of calyciphylline A-type Daphniphyllum alkaloids

Synthesis of Azabicyclic Building Blocks for Daphniphyllum Alkaloid Intermediates Featuring N‐Trichloroacetyl Enamide 5‐endo‐trig Radical Cyclizations

“…Some years ago, we began studying reactions to address some of the central issues in calyciphylline A‐type alkaloid synthesis. This allowed us to achieve the formation of the morphan nucleus by a Pd‐alkenylation of enolates, and the stereocontrolled installation of the axial methyl group in the piperidine ring, either by a substrate‐directed hydrogenation using Crabtree ’s catalyst or by α ‐alkylation of a lactam …”

Divergent Total Syntheses of (−)‐Daphnilongeranin B and (−)‐Daphenylline

“…From as tructural point of view,b oth 3 and 4 contain aseries of synthetically challenging structural features found in many calyciphylline At ype alkaloids,a nd they share ac ongested bowl-like hexacyclic substructure.T he [6.6.5.7.5.5] backbone of daphnilongeranin Bp ossesses seven stereogenic centers,f our of which are contiguous, including two vicinal quaternary centers.U nique to 4, however, is the highly fused hexacyclic [6.6.5.7.6.5] core containing ap eculiar tetrasubstituted benzene ring and six stereogenic centers;i ti st he only member of the Daphniphyllum alkaloids that contains an aromatic ring. [3][4][5] So far, there have been only two total syntheses of (À)-daphenylline (4), reported by the research groups of Li [5b] and Fukuyama/ Yokoshima. [3][4][5] So far, there have been only two total syntheses of (À)-daphenylline (4), reported by the research groups of Li [5b] and Fukuyama/ Yokoshima.…”

“…[3][4][5] So far, there have been only two total syntheses of (À)-daphenylline (4), reported by the research groups of Li [5b] and Fukuyama/ Yokoshima. [3] Herein, we describe the first total synthesis of (À)-daphnilongeranin Bas well as abioinspired total synthesis of (À)-daphenylline. [3] Herein, we describe the first total synthesis of (À)-daphnilongeranin Bas well as abioinspired total synthesis of (À)-daphenylline.…”

Total Synthesis of Isodaphlongamine H: A Possible Biogenetic Conundrum

“…[3] This seminal contribution paved the way to the elegant total syntheses of several members of this family by the Heathcock group. [5] However,e fforts toward the total synthesis of other complex Daphniphyllum alkaloids have been sparse. [5] However,e fforts toward the total synthesis of other complex Daphniphyllum alkaloids have been sparse.…”

“…Theu nique hexacyclic framework harboring an unprecedented C6/C7 cis-fused stereochemistry in the deoxycalyciphylline Bf amily,a sw ell as the intriguing biosynthetic intermediates,encouraged us to undertake the total synthesis of daphlongamine H(4)and its 5-epi isomer (5). We were also cognizant that as trategy which would produce ac ommon advanced intermediate could also be applicable toward the total synthesis of the biogenetically related deoxycalyciphylline B( 2)a nd deoxyisocalyciphylline B( 3) ( Figure 2).…”