91285-62-0Relevant academic research and scientific papers
BF3·OEt2-Catalyzed Unexpected Stereoselective Formation of 2,4-trans-Diallyl-2-methyl-6-aryltetrahydro-2 H-pyrans with Quaternary Stereocenters
Reddy, D. Srinivas,Srinivas, Beduru,Rachineni, Kavitha,Jagadeesh, Bharatam,Sarotti, Ariel M.,Mohapatra, Debendra K.
supporting information, p. 6518 - 6527 (2021/05/29)
The present manuscript describes a convenient, mild, and highly stereoselective method for the allylation of δ-hydroxy-α,β-unsaturated ketones having a benzylic hydroxyl group at the δ-position using allyltrimethylsilane mediated by BF3·OEt2, leading to 2,4-diallyl-2-methyl-6-aryltetrahydro-2H-pyran ring systems with quaternary carbon stereogenic centers. This represents the first example of a tandem isomerization followed by one C-O and two C-C bond-forming reactions in one pot. The isolation of TMS-protected lactol as an intermediate from the reaction strongly supports the proposed mechanistic pathway.
Development of a Practical, Biocatalytic Synthesis of tert-Butyl (R)-3-Hydroxyl-5-hexenoate: A Key Intermediate to the Statin Side Chain
Chen, Fener,Hu, Chen,Huang, Zedu,Liu, Minjie,Yue, Xiaoping
supporting information, p. 1700 - 1706 (2020/10/26)
The HMG-CoA reductase inhibitors, statins, are one of the most effective and bestselling cholesterol-lowering drugs. The use of statins has greatly extended people's lives and improved the quality of their life. Development of a more efficient, stereoselective, and sustainable synthesis of statins is continuingly of utmost importance. In the present study, through screening of ketoreductases (KREDs) and reaction optimization, we have successfully performed a highly stereoselective reduction of ketoester 1a catalyzed by KRED-06 at a pilot-plant scale without the addition of exogenous NADP+, generating 3.21 kg of enantiomerically pure tert-butyl (R)-3-hydroxyl-5-hexenoate ((R)-2a) (96.2% yield, >99.9% enantiomeric excess (ee)). This newly developed biocatalytic process alleviates the cryogenic conditions (-40 °C) employed in our first-generation synthesis of (R)-2a using NaBH4 and (l)-tartaric acid. Coupled with our previously established synthesis of bromocarbonate 3a via a one-pot diastereoselective carboxylation/bromocyclization of (R)-2a, we have developed an innovative, practical synthesis route to statin side chain, possessing great potential to be implemented into industrial production of statins.
Asymmetric Synthesis of Atorvastatin Calcium through Intramolecular Oxidative Oxygen-Nucleophilic Bromocyclization
Wu, Yan,Liu, Min-Jie,Huang, Hai-Qing,Huang, Guan-Xin,Xiong, Fang-Jun,Chen, Fen-Er
, p. 3681 - 3688 (2017/07/22)
The stereocontrolled synthesis of atorvastatin calcium starting from commercially available d-aspartic acid using an intramolecular oxidative oxygen-nucleophilic bromocyclization of a homoallylic tert-butyl carbonate is described. This strategy allows the formation of the chiral syn-1,3-diol moiety with the desired stereochemistry, and provides a functionalized bromomethyl group for the construction of the atorvastatin side-chain with high regio- and diastereoselectivity. This route is attractive as it represents an efficient and environmentally sensitive approach to the large-scale synthesis of statins and their analogues.
Total Synthesis of the 7,10-Epimer of the Proposed Structure of Amphidinolide N, Part II: Synthesis of C17-C29 Subunit and Completion of the Synthesis
Ochiai, Koji,Kuppusamy, Sankar,Yasui, Yusuke,Harada, Kenji,Gupta, Nishant R.,Takahashi, Yohei,Kubota, Takaaki,Kobayashi, Jun'ichi,Hayashi, Yujiro
supporting information, p. 3287 - 3291 (2016/03/05)
The total synthesis of 7,10-epimer of the proposed structure of amphidinolide N was accomplished. The requisite chiral C17-C29 subunit was assembled stereoselectively via Keck allylation, Shi epoxidation, diastereoselective 1,3-reduction, and a later oxidative synthesis of the THF framework. The C1-C13 and C17-C29 subunits were successfully coupled using a Enders RAMP "linchpin" as the C14-C16 three carbon unit, thereby controlling the chirality at C14 and C16. The labile allyl epoxy moiety was successfully constructed by Grieco-Nishizawa olefination at a final stage of the synthesis.
Intramolecular thermal stepwise [2 + 2] cycloadditions: Investigation of a stereoselective synthesis of [n.2.0]-bicyclolactones
Throup, Adam,Patterson, Laurence H.,Sheldrake, Helen M.
supporting information, p. 9554 - 9559 (2016/10/22)
Fused cyclobutanes are found in a range of natural products and formation of these motifs in a straightforward and easy manner represents an interesting synthetic challenge. To this end we investigated an intramolecular variant of the thermal enamine [2 + 2] cyclisation, developing a diastereoselective intramolecular enamine [2 + 2] cyclisation furnishing δ lactone and lactam fused cyclobutenes in good yield and excellent diastereoselectivity.
Synthesis of the Acyclic Carbon Skeleton of Filipin III
Brun, Elodie,Bellosta, Véronique,Cossy, Janine
, p. 8206 - 8221 (2016/09/28)
The synthesis of the carbon skeleton of filipin III, a polyenic macrolactone possessing 11 stereogenic centers, was achieved using a convergent strategy with the longest linear sequence of 19 steps starting from hexanal. Construction of the polyene was re
Substitution dependent stereoselective construction of bicyclic lactones and its application to the total synthesis of pyranopyran, tetraketide and polyrhacitide A
Subba Reddy,Biradar, Dhanraj O.,Vikram Reddy,Yadav,Singarapu, Kiran Kumar,Sridhar
supporting information, p. 8832 - 8837 (2016/10/03)
A novel bicyclization strategy has been developed for the stereoselective synthesis of bicyclic lactones, i.e. 7-aryl or alkyl-2,6-dioxabicyclo[3.3.1]nonan-3-ones through a domino cyclization of (R)-3-hydroxyhex-5-enoic acid with an aldehyde in the presen
Asymmetric Synthesis of Borylalkanes via Copper-Catalyzed Enantioselective Hydroallylation
Han, Jung Tae,Jang, Won Jun,Kim, Namhyeon,Yun, Jaesook
supporting information, p. 15146 - 15149 (2016/12/06)
An efficient synthetic method for preparing enantioenriched secondary borylalkanes has been achieved through a copper-catalyzed regio- and enantioselective hydroallylation of alkenyl boronates and boramides employing hydrosilanes and allylic phosphates. In the presence of a copper catalyst with a chiral Walphos ligand, a range of alkenylboron compounds with an aryl, heteroaryl, or alkyl substituent produced secondary homoallylic alkylboron compounds in good yields and with high enantioselectivities up to 99% ee. The utility of the resulting alkylboronates was demonstrated in an efficient synthesis of (S)-massoialactone.
A concise stereoselective total synthesis of diplodialide C
Pratapareddy, Bommareddy,Sreenivasulu, Reddymasu,Hatti, Islavathu,Venkata Basaveswara Rao, Mandava,Raju, Rudraraju Ramesh
, p. 1921 - 1926 (2015/10/29)
An asymmetric total synthesis of diplodialide C has been achieved starting from commercially available homoallylic alcohol. Regioselective opening of the chiral epoxide, cross-metathesis reaction, and Yamaguchi macrolactonization were used as the key step
Simple stereoselective synthesis of unsaturated lactone intermediates and their conversion into natural dihydropyranones and their enantiomers#
Shinde, Digambar Balaji,Kanth, Boddu Shashi,Satyakumar, Avula,Kamble,Das, Biswanath
, p. 317 - 323 (2013/07/26)
The stereoselective synthesis of the unsaturated lactone intermediates, (S) - and (R)-2-(6-oxo-3, 6-dihydro-2Hpyran-2-yl) acetaldehydes has been accomplished from propane 1,3 diol employing Maruoka asymmetric allylation and ring closing metathesis reaction. The intermediates were converted into two natural dihydropyranones, 6 (R)-4-oxopent-2-enyl 5,6-dihydro-2H-pyran-2-one and (R)- rugulactone and their enantiomers through Wittig olefination.
