Stereocomplementary Construction of Optically Active Bicyclo[4.3.0]nonenone Derivatives
摘要:
Treatment of (5S,6S)-5,6-bis(tert-butyldimethylsiloxy)-8-(substituted)oct-1-en-7-yne derivatives, prepared from diethyl L-tartrate, with Co-2(CO)(8) afforded the corresponding cobalt-complexed enynes, which were subsequently exposed to the typical Pauson-Khand conditions to furnish highly stereoselectively or exclusively (2S,3S,6S)-2,3-bis(tert-butyldimetbylsiloxy)-9-(substituted)bicyclo[4.3.0]non-1(9)-en-8-ones. On the other hand, (3S,4S)-1-(substituted)oct-7-en-1-yne-3,4-diol congeners produced, on exposure to the Pauson-Khand conditions, (2S,3S,6R)-2,3-dihydroxy-9-(substituted) bicyclo[4.3.0]-non-1(9)-en-8-one derivatives in a highly stereoselective manner. The newly developed procedure has been shown to be useful for construction of the 2,3-bis(oxygenated)-7-(substituted)-bicyclo[4.3.0]non-6-en-8-one framework in a stereocomplementary as well as stereoselective fashion.
Stereocomplementary Construction of Optically Active Bicyclo[4.3.0]nonenone Derivatives
摘要:
Treatment of (5S,6S)-5,6-bis(tert-butyldimethylsiloxy)-8-(substituted)oct-1-en-7-yne derivatives, prepared from diethyl L-tartrate, with Co-2(CO)(8) afforded the corresponding cobalt-complexed enynes, which were subsequently exposed to the typical Pauson-Khand conditions to furnish highly stereoselectively or exclusively (2S,3S,6S)-2,3-bis(tert-butyldimetbylsiloxy)-9-(substituted)bicyclo[4.3.0]non-1(9)-en-8-ones. On the other hand, (3S,4S)-1-(substituted)oct-7-en-1-yne-3,4-diol congeners produced, on exposure to the Pauson-Khand conditions, (2S,3S,6R)-2,3-dihydroxy-9-(substituted) bicyclo[4.3.0]-non-1(9)-en-8-one derivatives in a highly stereoselective manner. The newly developed procedure has been shown to be useful for construction of the 2,3-bis(oxygenated)-7-(substituted)-bicyclo[4.3.0]non-6-en-8-one framework in a stereocomplementary as well as stereoselective fashion.
Structure and Absolute Stereochemistry of the Anticancer Agent EBC-23 from the Australian Rainforest
作者:Lin Dong、Victoria A. Gordon、Rebecca L. Grange、Jenny Johns、Peter G. Parsons、Achim Porzelle、Paul Reddell、Heiko Schill、Craig M. Williams
DOI:10.1021/ja807133p
日期:2008.11.19
EBC-23 (2), a prostate anticanceragent, was isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australiantropicalrainforest. Extensive NOE experiments enabled the relative stereochemistry of the proposed EBC-23 (2) structure to be determined. Total synthesis of both enantiopodes over nine linear steps, involving challenging RCM and spiroacetal cyclizations, confirmed the gross
Stereoselective epoxidation of divinylmethanol: A synthetic approach to the pentitols
作者:David Holland、J. Fraser Stoddart
DOI:10.1016/s0008-6215(00)81036-8
日期:——
-butyl hydroperoxide with catalytically active Ti 4+ , V 5+ , or Mo 6+ complexes are employed as epoxidation reagents. However, the diastereoselectivities characterising the epoxidations and the regioselectivities governing the epoxide-ring openings are not sufficiently high to constitute an attractive synthesis of either ribitol, dl -arabinitol, or xylitol from divinylmethanol.
Stereoselective synthesis of protected <scp>l</scp>- and <scp>d</scp>-dideoxysugars and analogues via Prins cyclisations
作者:Ryan J. Beattie、Thomas W. Hornsby、Gemma Craig、M. Carmen Galan、Christine L. Willis
DOI:10.1039/c5sc04144a
日期:——
Cyclisation of a silicon acetal with homoallylic alcohols to generate silyltetrahydropyrans and subsequent oxidation gives rapid access to deoxyglycoside analogues.
Anticancer Agents from the Australian Tropical Rainforest: Spiroacetals EBC-23, 24, 25, 72, 73, 75 and 76
作者:Lin Dong、Heiko Schill、Rebecca L. Grange、Achim Porzelle、Jenny P. Johns、Peter G. Parsons、Victoria A. Gordon、Paul W. Reddell、Craig M. Williams
DOI:10.1002/chem.200901525
日期:2009.10.26
EBC‐23, 24, 25, 72, 73, 75 and 76 were isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australiantropicalrainforests. EBC‐23 (1) was synthesized stereoselectively, in nine linear steps in 8 % overall yield, to confirm the reported relative stereochemistry and determine the absolute stereochemistry. Key to the total synthesis was a series of Tietze–Smith linchpin reactions
strategy has been used for the concise and efficient enantioselective formal synthesis of Annonaceous acetogenin cis-solamin. Our synthetic strategy comprises concise preparation of the diepoxyester via an 11-membered silaketal constructed by ring-closing metathesis after the dimerization of chiral epoxides, and uses an acid-catalyzed tandem intramolecular SN2-like reaction to construct the threo-cis-threo
已经采用了一种不同的策略来简便,高效地合成Annanoaceous acetogenin顺式-solamin的对映选择性形式。我们的合成策略包括通过手性环氧化物二聚后通过闭环易位而构建的11元硅酮来制备二环氧酯,并使用酸催化的串联分子内S N 2类反应来构建苏式-顺式-苏式四氢呋喃-二醇部分的构型。