6750-34-1Relevant articles and documents
Enantioselective Total Synthesis of the Archaeal Lipid Parallel GDGT-0 (Isocaldarchaeol)**
Falk, Isaac D.,Gál, Bálint,Bhattacharya, Ahanjit,Wei, Jeremy H.,Welander, Paula V.,Boxer, Steven G.,Burns, Noah Z.
supporting information, p. 17491 - 17496 (2021/06/15)
Archaeal glycerol dibiphytanyl glycerol tetraethers (GDGT) are some of the most unusual membrane lipids identified in nature. These amphiphiles are the major constituents of the membranes of numerous Archaea, some of which are extremophilic organisms. Due to their unique structures, there has been significant interest in studying both the biophysical properties and the biosynthesis of these molecules. However, these studies have thus far been hampered by limited access to chemically pure samples. Herein, we report a concise and stereoselective synthesis of the archaeal tetraether lipid parallel GDGT-0 and the synthesis and self-assembly of derivatives bearing different polar groups.
A novel highly enantio- and diastereoselective synthesis of vitamin e side-chain
Matsueda, Yohei,Xu, Shiqing,Negishi, Ei-Ichi
, p. 3346 - 3348 (2015/06/02)
A novel highly enantioselective (>99% ee) and diastereoselective (>98% de) method for the synthesis of chiral C15 vitamin E side-chain 1 was developed. ZACA-lipase-catalyzed acetylation protocol to provide a key α,ω-dioxyfunctional C5/sub
Tocopherol side chain synthesis via asymmetric organocatalytic transfer hydrogenation and convenient measurement of stereoselectivity
Lee, Hyunji,Lee, You-Kyoung,Kim, Dong-Guk,Son, Mi-Sun,Nam, Tae-Gyu,Jeong, Byeong-Seon
, p. 5895 - 5897 (2014/12/12)
An asymmetric synthetic route for 1-iodofarnesane, a key intermediate for tocopherol side chain synthesis, starting from (+)-(R)-citronellal was developed. 1-Iodofarnesane was prepared through eight steps in about 50% overall yield, and asymmetric transfe
Enantio- and diastereoselective hydrogenation of farnesol and O-protected derivatives: Stereocontrol by changing the C=C bond configuration
Wang, Aie,Wuestenberg, Bettina,Pfaltz, Andreas
, p. 2298 - 2300 (2008/12/23)
(Chemical Presented) Four isomers-one catalyst: The four stereoisomers of hexahydrofarnesol can be prepared with high enantio- and diastereoselectivity by using the same chiral iridium catalyst 1 with different cis/trans isomers of farnesol (see scheme; B
ASYMMETRIC HYDROGENATION OF ALKENNES USING CHIRAL IRIDIUM COMPLEXES
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Page/Page column 19, (2008/06/13)
The invention relates to the (stereoselective) hydrogenation of carbon-carbon double bonds in compounds having at least one such bond, e.g., isoprenoids, non-cyclic sesquiterpenes, tocomonoenols, tocodienols, tocotrienols or derivatives thereof, as well as to the (stereoselective) hydrogenation of parts/extracts of plant oils containing such tocotrienols or derivatives thereof, in the presence of a chiral Ir complex as the catalyst, whereby preferably one stereoisomer is manufactured in an excess.
Stereocontrol of 1,5-related stereocentres using an intermediate silyl group-the diastereoselectivity of nucleophilic attack on a double bond adjacent to a stereogenic carrying a silyl group
Fleming, Ian,Maiti, Pranab,Ramarao, Chandrashekar
, p. 3989 - 4004 (2007/10/03)
R-5-Methylcyclohex-2-enone 1 reacts successively with the phenyldimethylsilylzincate reagent and acetaldehyde to give with regiocontrol the aldols 7, dehydration of which creates the E-exocyclic double bond of the α-β-unsaturated ketone 2. Conjugate addition of the ethylcuprate reagent to this compound takes place with high (96 : 4) selectivity in favour of the R stereoisomer 12, hydrolysis of which gives (2R,3R,5S,2′ R)-2-(but-2′-yl)-3-dimethyl(phenyl)silyl-5-methylcyclohexanone 3. The oxime acetate of this ketone undergoes fragmentation in the presence of trimethylsilyl trifluoromethanesulfonate to give 3R,7R,5E-3,7-dimethylnon-5-enonitrile 4, in which an open-chain 1,5-stereo-chemical relationship is set up with a high level of stereocontrol. A similar sequence adding 4-methylpentylcuprate to the enone 2, and fragmentation gives 3R,7R,5E-3,7,11-trimethyldodec-5-enonitrile 20. Reduction and hydrogenation of this nitrile gives 3R,7R-3,7,11 -trimethyldodecanal 22, which can be converted into phytol 25. The ketoaldehyde 29 reacts with samarium iodide to give only the alcohol 30, in which the radical anion has attacked from the top surface, just like the cuprate reagents in their reactions with the ketone 2.
A new protocol for the enantioselective synthesis of methyl-substituted alkanols and their derivatives through a hydroalumination/zirconium-catalyzed alkylalumination tandem process
Huo, Shouquan,Shi, Ji-Cheng,Negishi, Ei-Ichi
, p. 2141 - 2143 (2007/10/03)
Methyl-substituted alkanols have been synthesized enantioselectively (90-93% ee) in a one-pot hydroalumination/carboalumination tandem process (see scheme). This enantioselectively represents an increase of about 15% from the previously attainable ee values. DIBAH = diisobutylaluminum hydride, IBAO = isobutylaluminoxane.
Enantioselective synthesis of (2R,4'R,8'R)-α-tocopherol (Vitamin E) based on enzymatic function
Nozawa, Masako,Takahashi, Keiko,Kato, Keisuke,Akita, Hiroyuki
, p. 272 - 277 (2007/10/03)
Syntheses of (S)-chroman-2-carboxaldehyde congener 1 and (S)-chiral isoprene unit 3 were achieved based on the enzymatic acetylation of (±)- chroman-2-methanol 6 and (±)-(2,3)-anti-2-methyl-3-(p-methoxyphenyl)-1,3- propane diol 12, respectively. Synthesis of the side-chain part corresponding to (3R,7R)-3,7,11-trimethyldodecan-1-ol 27 was achieved by the coupling reaction of (S)-3 and (R)-3,7-dimethyloctyl iodide 4. The Wittig reaction of (3R,7R)-phosphonium salt 2 derived from (3R,7R)-27 and (S)-1 gave the olefin 28 which was subjected to catalytic hydrogenation to afford (2R,4'R,8'R)-α- tocopherol.
Synthesis of archaebacterial lipid C20 chirons
Berkowitz, William F.,Yanzhong, Wu
, p. 8141 - 8144 (2007/10/03)
Archaebacterial lipid C20 chirons were synthesized by cross-coupling optically active C10 'dimer' units prepared from hydroxyester 7. Vitamin E (C15) side chain was similarly constructed.
A synthesis of (2R,4'R,8'R)-α-tocopherol (vitamin E) side chain
Chen, Cheng Yu,Nagumo, Shinji,Akita, Hiroyuki
, p. 2153 - 2156 (2007/10/03)
Optically pore (3R,7R)-3,7,11-trimethyldodecan-1-ol (16), corresponding to the α-tocopherol side chain, was synthesized by the coupling reaction of a chiral isoprene unit (3S)-9 derived from an enzymatically hydrolyzed product (2S,3S)-2 and a ten-carbon alkylating reagent (R)-13 derived from (R)-(+)-pulegone.