Hydrolysis and selective reduction with yeast: enantiospecific synthesis of antirhine from secologanin
作者:Richard T. Brown、Bukar E. N. Dauda、Cid A. M. Santos
DOI:10.1039/c39910000825
日期:——
Glucoside hydrolysis and chemoselective reduction of secologanin ethylene acetal 2 with baker's yeast affords a C-1 reduced aglucone 4 from which (+)-antirhine 8 is obtained in a four-step sequence.
Synthesis of a potential synthon for the chiral synthesis of the corynanthe-type indole alkaloids: enantioselective total synthesis of (–)-antirhine
作者:Seiichi Takano、Nobuhiko Tamura、Kunio Ogasawara
DOI:10.1039/c39810001155
日期:——
The chiral formylmethyl(vinyl)tetrahydro-pyranone (16), a potential versatile synthon for the chiralsynthesis of the Corynanthe-typeindolealkaloids, has been synthesised and converted into (–)-antirhine, the major alkaloid of Antirhea putaminosa(F. Muell.) Bail.
(−)-Antirhine 2 was synthesized in an efficient and stereocontrolled fashion from the readily available (1R-2S)-cyclohexene dimethanol monoacetate 6. A key step was the regio- and stereoselective Pictet Spengler cyclization of the masked dialdehyde 12 to the indoloquinolizidinone 13.
Total synthesis of (-)-antirhine (5) has been achieved from a potentially useful chiral synthon, (3R)-[3-hydroxy-(E)-prop-1-enyl]cyclopentanone (2) [derived from (R)-1, 2-isopropylideneglyceraldehyde (1)], via the β, γ-unsaturated aldehyde (12), which was obtained by mild hydrolysis of the α-cyano-N, N-dimethylaminocyclopentanone (11).
Enantio- and stereocontrolled syntheses of (−)-semburin, (+)-N-benzoylmeroquinene aldehyde, (−)-antirhine, and (+)-isocorynantheol from common (+)-norcamphor
作者:Mitsuhiro Kawamura、Kunio Ogasawara
DOI:10.1016/0040-4039(95)00543-l
日期:1995.5
A general enantio- and stereocontrolled route to the representative secologanin natural products, (−)-semburin, (+)-N-benzoylmeroquinene aldehyde, (−)-antirhine, and (+)-isocorynantheol, has been developed starting from (+)-norcamphor as a common chiral building block.