121469-49-6Relevant articles and documents
Tandem ring-closing/cross-metathesis approach for the synthesis of synargentolide B and its stereoisomers
Sabitha, Gowravaram,Shankaraiah, Kontham,Yadav, Jhillu S.
, p. 4870 - 4878 (2013/08/23)
The stereoselective syntheses of synargentolide B and its three stereoisomers have been accomplished from L-(+)- and D-(-)-diethyl tartrates, D-ribose, and D-mannitol as chiral pool starting materials. The key step was a tandem ring-closing/cross-metathes
Stereoselective total synthesis of seimatopolide a
Bhunia, Nisith,Das, Biswanath
, p. 1633 - 1642 (2014/01/17)
Stereoselective total synthesis of the naturally occurring bioactive macrolide, seimatopolide A has been achieved starting from commercially available (+)-diethyl tartrate. Chelation-controlled Grignard reaction, Yamaguchi esterification, ring closing cross metathesis and CBS reduction reactions are involved as key steps.
On the origins of diastereoselectivity in the conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and trans-dioxolane containing α,β-unsaturated esters
Davies, Stephen G.,Foster, Emma M.,Frost, Aileen B.,Lee, James A.,Roberts, Paul M.,Thomson, James E.
, p. 6186 - 6200 (2012/09/05)
"Matching" and "mismatching" effects in the doubly diastereoselective conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and trans-dioxolane containing α,β-unsaturated esters have been investigated. High levels of substrate control were established first upon conjugate addition of achiral lithium N-benzyl-N-isopropylamide to both tert-butyl (S,S,E)-4,5-O- isopropylidene-4,5-dihydroxyhex-2-enoate and tert-butyl (4R,5S,E)-4,5-O- isopropylidene-4,5-dihydroxyhex-2-enoate. However, upon conjugate addition of lithium (R)-N-benzyl-(N-α-methylbenzyl)amide and lithium (S)-N-benzyl-(N-α-methylbenzyl)amide to these substrates, neither reaction pairing reinforced the apparent sense of substrate control. These reactions do not, therefore, conform to the classical doubly diastereoselective "matching" or "mismatching" pattern usually exhibited by this class of reaction. A comparison of these reactions with the previously reported doubly diastereoselective conjugate addition reactions of lithium amide reagents to analogous substrates is also discussed.
Stereocomplementary Construction of Optically Active Bicyclo[4.3.0]nonenone Derivatives
Mukai, Chisato,Kim, Jin Sung,Sonobe, Hiroshi,Hanaoka, Miyoji
, p. 6822 - 6832 (2007/10/03)
Treatment of (5S,6S)-5,6-bis(tert-butyldimethylsiloxy)-8-(substituted)oct-1-en-7-yne derivatives, prepared from diethyl L-tartrate, with Co2(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-butyldimethylsiloxy)-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,6A)-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.
D-Erythronolactone and 2,3-O-Isopropylidene-L-erythrose as C4 Building Units: An Efficient Synthesis of both Enantiomers of endo-Brevicomin and its 7-Vinyl Analogues
Gypser, Andreas,Flasche, Michael,Scharf, Hans-Dieter
, p. 775 - 780 (2007/10/02)
Both enantiomers of endo-brevicomin (+)- and (-)-3a were synthesized from D-erythronolactone (1) and 2,3-O-isopropylidene-L-erythrose (2), respectively.In the course of the synthesis also the 7-vinyl analogues (+)- and (-)-3b of endo-brevicomin are available.The key step of the synthesis is the diastereoselective acetalization of the diols 1 and 10 with 4-(phenylsulfonyl)-2-butanone (4) and boron trifluoride-diethyl ether complex as a catalyst.The described procedure yields the key compounds 5a and ent-7b in good yields and with high diastereomeric purity. - Key Words: Brevicomin / Erythronolactone / Acetalization, diastereoselective / Erythrose, 2,3-O-isopropylidene- / Pheromones
ASYMMETRIC SHARPLESS EPOXIDATION OF DIVINYLCARBINOL. erythro-D- AND -L-4-PENTENITOLS BY HYDROLYSIS OF REGIOISOMERIC EPOXY-4-PENTENOLS
Jaeger, Volker,Schroeter, Detlef,Koppenhoefer, Bernhard
, p. 2195 - 2210 (2007/10/02)
The asymmetric Sharpless epoxidation of divinylcarbinol (1), a secondary, achiral allylic alcohol, is described in detail.The epoxidation proceeds with high enantio-control and diastereo-selection.The resulting 1,2-epoxy-4-pentene-3-ols 2 are equilibrated to afford the internal epoxides 5.Hydrolysis of the regioisomers 2 and 5, respectively, furnishes opposite enantiomers of erythro-4-pentenitols 3 with high selectivity.Several derivatives of 3 are described, as well as result of a less stereoselective route - from D-glyceraldehyde acetonide (10) - providing NMR data of the threo series. - The acute toxicity of divinylcarbinol (1) is reported, along with the mutagenicity of 1, L-2 and L-5 as determined by Ames tests.
Synthesis of Side-Chain Unsaturated endo- and exo-Brevicomins. Representatives of Pheromone Analogs in the Dioxabicyclooctane Series
Wershofen, Stefan,Scharf, H.-D.
, p. 854 - 858 (2007/10/02)
The title substances endo- and exo-9 were synthesized via selective trans- and cis-opening of the epoxy tosylate 3, respectively.The tosylate 3 is easily obtainable from pentadienol 1.
Synthesis of Optically Active Olefinic Building Blocks from D-Ribonolactone: Isopropylidene Derivatives of D-erythro-Pentenediol and -triol (cis-4-Substituted 5-Vinyldioxolanes)
Jaeger, Volker,Haefele, Brigitte
, p. 801 - 806 (2007/10/02)
Optically active D-erythro-pentenediol and triol acetonides 4-11 were prepared from D-ribonolactone 1, via the acid 4 and the alcohol 9 as key intermediates.Acetonides 4-11 are cis-4-substituted 5-vinyldioxolanes, both needed as standard model substrates
