Acortatarins A and B have been synthesized via stereoselective spirocyclizations of glycals. Mercury-mediated spirocyclization of a pyrrole monoalcohol side chain leads to acortatarin A. Glycal epoxidation and reductive spirocyclization of a pyrrole dialdehyde side chain leads to acortatarin B. Acid equilibration and crystallographic analysis indicate that acortatarin B is a contrathermodynamic spiroketal with distinct ring conformations compared to acortatarin A.
Acortatarins A and B have been synthesized via stereoselective spirocyclizations of glycals. Mercury-mediated spirocyclization of a pyrrole monoalcohol side chain leads to acortatarin A. Glycal epoxidation and reductive spirocyclization of a pyrrole dialdehyde side chain leads to acortatarin B. Acid equilibration and crystallographic analysis indicate that acortatarin B is a contrathermodynamic spiroketal with distinct ring conformations compared to acortatarin A.
Boron-containing nucleic acids. Synthesis of cyanoborane adducts of 2'-deoxynucleosides
作者:Anup Sood、Barbara Ramsay Shaw、Bernard F. Spielvogel
DOI:10.1021/ja00208a019
日期:1989.12
Cyanoborane adducts of 2'-deoxynucleosides, specifically 2'-deoxyguanosine-N7-cyanoborane, 2'-deoxyadenosine-N1-cyanoborane, 2'-deoxyinosine-N7-cyanoborane, and 2'-deoxycytidine-N3-cyanoborane, were prepared by an exchange reaction of triphenylphosphine-cyanoborane (Ph 3 PBH 2 CH) with 3',5'-O-protected nucleosides
An efficient one step procedure for the preparation of (4.3.0) bicyclic N-methylpyrrolidine thymidine derivatives 4, using cycloaddition reaction of the highly reactive non-stabilized azomethine ylide [Y] with 3',5'-Bis-O-silylthymidines 3.
Stereoselective Synthesis of Acortatarins A and B
作者:Jacqueline M. Wurst、Alyssa L. Verano、Derek S. Tan
DOI:10.1021/ol3019456
日期:2012.9.7
Acortatarins A and B have been synthesized via stereoselective spirocyclizations of glycals. Mercury-mediated spirocyclization of a pyrrole monoalcohol side chain leads to acortatarin A. Glycal epoxidation and reductive spirocyclization of a pyrrole dialdehyde side chain leads to acortatarin B. Acid equilibration and crystallographic analysis indicate that acortatarin B is a contrathermodynamic spiroketal with distinct ring conformations compared to acortatarin A.