112083-27-9Relevant academic research and scientific papers
Asymmetric synthesis of (+)-negamycin
Davies, Stephen G.,Ichihara, Osamu
, p. 1919 - 1922 (1996)
(+)-Negamycin was synthesised employing the highly diastereoselective conjugate addition of lithium (α-methylbenzyl)benzylamide in the key step. The synthesis was completed in 13 steps starting from ethyl 4-chloroacetoacetate with an overall yield of 24%.
Enantiomerically pure β,γ-epoxyesters from β-hydroxylactones: Synthesis of β-hydroxyesters and (-)-GABOB
Larcheveque,Henrot
, p. 4277 - 4282 (1990)
The preparation of enantiomerically pure β,γ-epoxyesters was achieved by chemoselective opening of β-hydroxybutanolides with trimethylsilyliodide followed by cyclisation of the resulting iodohydrins with silver oxide. The reaction of these epoxyesters with lithio or magnesiocuprates afforded stereochemically pure α-substituted β-hydroxyesters. Alternatively, (-)-GABOB was synthesized in optically pure form from the iodohydrin 2′a.
PREPARATION DE NOUVEAUX SYNTHONS CHIRAUX: LES β,γ-EPOXYESTERS; APPLICATION A LA SYNTHESE DE β-HYDROXYESTERS ENANTIOMERIQUEMENT PURS
Larcheveque, Marc,Henrot, Serge
, p. 1781 - 1782 (1987)
The preparation of optically pure β,γ-epoxyesters 3 has been achieved through the opening of 3-hydroxybutanolides with trimethylsilyliodide followed by cyclisation with silver oxyde.They react with organocuprates to afford β-hydroxyesters of high enantiomerical purity.
Cation-π interactions contribute to substrate recognition in γ-butyrobetaine hydroxylase catalysis
Kamps, Jos J. A. G.,Khan, Amjad,Choi, Hwanho,Lesniak, Robert K.,Brem, Jürgen,Rydzik, Anna M.,McDonough, Michael A.,Schofield, Christopher J.,Claridge, Timothy D. W.,Mecinovic, Jasmin
, p. 1270 - 1276 (2016)
γ-Butyrobetaine hydroxylase (BBOX) is a non-heme FeII- and 2-oxoglutarate-dependent oxygenase that catalyzes the stereoselective hydroxylation of an unactivated C-H bond of γ-butyrobetaine (γBB) in the final step of carnitine biosynthesis. BBOX contains an aromatic cage for the recognition of the positively charged trimethylammonium group of the γBB substrate. Enzyme binding and kinetic analyses on substrate analogues with P and As substituting for N in the trimethylammonium group show that the analogues are good BBOX substrates, which follow the efficiency trend N+>P+>As+. The results reveal that an uncharged carbon analogue of γBB is not a BBOX substrate, thus highlighting the importance of the energetically favorable cation-π interactions in productive substrate recognition. What's in the BBOX? Enzyme kinetics and substrate binding studies reveal that γ-butyrobetaine hydroxylase (BBOX)-catalyzed stereoselective hydroxylation of γ-butyrobetaine involves energetically favorable cation-π interactions.
A Concise Stereoselective Total Synthesis of Methoxyl Citreochlorols and Their Structural Revisions
Sunnapu, Ranganayakulu,Rajendar, Goreti
, p. 1637 - 1642 (2021/03/15)
A concise, stereoselective and protecting group free approaches for the total synthesis of (?)-(2S,4R)- and (+)-(2R,4S)-3′-methoxyl citreochlorols and their stereoisomers are demonstrated. All four stereoisomers were synthesized to establish the absolute stereochemistry of the reported structures and the structures were revised accordingly. The approach involves chelation controlled regioselective reduction of a diester, silyl iodide promoted ring-opening iodo esterification of lactones, highly chemo- and regioselective ring-opening of an epoxy ester, dichloromethylation of a carboxyl group, and syn- and anti-selective reduction of the resulted β-hydroxy ketone as key steps.
SUBSTITUTED STRAIGHT CHAIN SPIRO DERIVATIVES
-
Page/Page column 115, (2021/06/26)
Provided herein are pharmaceutical agents useful for therapy and/or prophylaxis in a mammal, pharmaceutical composition comprising such compounds, and their use as menin/MLL protein/protein interaction inhibitors, useful for treating diseases such as cancer, including but not limited to leukemia, myelodysplastic syndrome (MDS), and myeloproliferative neoplasms (MPN); and diabetes.
Diverse synthesis of the C ring fragment of bryostatins via Zn/Cu-promoted conjugate addition of α-hydroxy iodide with enone
Chu, Zhiwen,Tong, Ruiqi,Yang, Yufan,Song, Xuanyi,Hu, Tian bao,Fan, Yu,Zhao, Chen,Gao, Lu,Song, Zhenlei
supporting information, p. 1 - 4 (2020/12/21)
A convergent approach to 1,5-hydroxy ketones, the general precursors for constructing the C ring of bryostatins, has been developed via a Zn/Cu-promoted conjugate addition of α-hydroxy iodides with enones. The reaction leads to direct formation of the C21-C22 bond and tolerates diverse functionalities at the C17-, C18- and C24-positions. The approach also enables a more concise synthesis of the known C ring intermediate (10 longest linear steps and 14 total steps), in contrast to its previous synthesis (17 longest linear steps and 22 total steps) in our total synthesis of bryostatin 8.
Synthesis of epigoitrin from (R)-(+)-4-hydroxy-γ-butyrolactone
Yin, Wei,Qiao, Chunhua
, p. 1290 - 1293 (2014/01/06)
Epigoitrin is one of the major components of several natural species, including Isatis indigotica Fort, turnip, and cabbage. It presents antithyroid and antivirus activities. Here, we report an efficient and practical method for the chemical synthesis of epigoitrin from commercially available (R)-(+)-4-hydroxy-γ-butyrolactone.
Asymmetric syntheses of (+)-negamycin, (+)-3-epi-negamycin and sperabillin C via lithium amide conjugate addition
Davies, Stephen G.,Ichihara, Osamu,Roberts, Paul M.,Thomson, James E.
, p. 216 - 227 (2011/03/17)
The chemo- and enantioselective reduction of ethyl 4-chloroacetoacetate and the diastereoselective conjugate addition of enantiopure lithium N-benzyl-N-(α-methylbenzyl)amide to an α,β-unsaturated ester have been used as the key steps in the total asymmetric syntheses of (+)-negamycin (in 13 steps and 24% overall yield), (+)-3-epi-negamycin (in 13 steps and 10% overall yield) and sperabillin C (in 17 steps and 13% overall yield) from commercially available starting materials.
Synthesis of optically active 5-(tert-butyldimethylsiloxy)-2- cyclohexenone and its 6-substituted derivatives as useful chiral building blocks for the synthesis of cyclohexane rings. Synthesis of carvone, penienone, and penihydrone
Hareau, Georges P.-J.,Koiwa, Masakazu,Hikichi, Shinichi,Sato, Fumie
, p. 3640 - 3650 (2007/10/03)
Optically active 5-(tert-butyldimethylsiloxy)-2-cyclohexenone (1) and its 6-substituted derivatives 2a,b were synthesized from the readily available optically active ethyl 3-(tert-butyldimethylsiloxy)-5-hexenoate (4), where the Ti(II)-mediated intramolecular nucleophilic acyl substitution reaction and the FeCl3-mediated ring expansion reaction of a 1- hydroxybicyclo[3.1.0]hexane are the key reactions. The enone 1 reacted with higher-order cyanocuprates with excellent diastereoselectivity to afford the trans-addition products, trans-13, in excellent yields. The reaction of 1 with lower-order cyanocuprates proceeded with moderate to excellent syn- selectivity to afford cis-13. Treatment of trans- and cis-13 with DBU (1,8- diazabicyclo[5.4.0]undec-7-ene) or catalyst p-TSA (p-toluenesulfonic acid) resulted in a β-elimination reaction to furnish the corresponding optically active 5-substituted-2-cyclohexenones 14. The 1,4-addition reaction of 2a and 2b with organocy-anocuprates followed by treatment of the resulting 20 with DBU provided the 2,5-disubstituted-2-cyclohexenones 19 with excellent ee. The conversion of 14 into the 3,5-disubstituted-2-cyclohexenone 22 has also been carried out via 1,2-addition of alkyllithium onto the carbonyl group and the following oxidation with PCC (pyridinium chlorochromate). Similarly, the conversion of 19 into 2,3,5-trisubstituted-2-cyclohexenones 24 has been carried out. A highly efficient, first total synthesis of penienone 25 and penihydrone 26 has been accomplished. Thus, the 1,4-addition reaction of 1 with the (E,E)-1,3-heptadienyl cyanocuprate and consecutive trap of the resulting copper enolate with formaldehyde gave 28, which upon treatment with DBU or Pyr · HF yielded 25 and 26, respectively. An efficient synthesis of both enantiomers of carvone starting from (S)-20ab has been also accomplished.
