Chemoenzymatic total synthesis of ent-neopinone and formal total synthesis of ent-codeinone from β-bromoethylbenzene*

2011 ◽  
Vol 89 (6) ◽  
pp. 709-729 ◽  
Author(s):  
Jan Duchek ◽  
T. Graeme Piercy ◽  
Jacqueline Gilmet ◽  
Tomas Hudlicky
Keyword(s):  
Total Synthesis ◽  
Heck Reaction ◽  
Aldol Condensation ◽  
Side Chain ◽  
Prins Reaction ◽  
Toluene Dioxygenase ◽  
E Coli ◽  
Key Steps ◽  
New Compounds ◽  
Stereogenic Center

Formal total synthesis of ent-codeinone and ent-codeine was accomplished via the total synthesis of ent-neopinone attained in 14 steps from β-bromoethylbenzene. The key steps included (i) enzymatic dihydroxylation of β-bromoethylbenzene with E. coli JM109 (pDTG601a), an organism that overexpresses toluene dioxygenase, (ii) a Heck reaction to establish C-13 stereogenic center, (iii) aldol condensation, and (iv) 1,6-conjugate addition of the ethylamino side chain to C-9. Several other modes of construction of the C-9 and C-14 centers were also investigated: Mannich cyclization, and aza-Prins reaction. The synthesis of ent-codeinone was formalized by intersecting Fukuyama’s recently published approach. Experimental and spectral data are provided for all new compounds.

Chemoenzymatic Formal Total Synthesis of Pancratistatin from Narciclasine-Type Compounds via Myers Transposition: Model Study for a Short Conversion of Narciclasine to Pancratistatin

Synlett ◽  
2017 ◽  
Vol 28 (20) ◽  
pp. 2896-2900 ◽  
Author(s):  
Ringaile Lapinskaite ◽  
Mukund Ghavre ◽  
Chelsea Rintelmann ◽  
Korey Bedard ◽  
Helen Dela Paz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Recombinant Strain ◽  
Optical Purity ◽  
Allylic Alcohol ◽  
Formal Synthesis ◽  
Toluene Dioxygenase ◽  
Single Isomer ◽  
Model Study ◽  
New Compounds ◽  
Subsequent Opening

A formal total synthesis of pancratistatin was accomplished by conversion of advanced intermediates, used in the synthesis of narciclasine, to pancratistatin precursors via Myers’ reductive transposition as the key strategic step. The synthesis began with the whole cell fermentation of m-dibromobenzene with JM109(pDTG601a), a recombinant strain that over-expresses toluene dioxygenase, which provided the corresponding cis-dihydrodiol 16 as a single isomer with complete optical purity. The key reductive transposition of the allylic alcohol 8a to olefin 9a allowed for further installation of the C-1/C-2 trans-diol, ­required for the pancratistatin scaffold, through the introduction of a cyclic sulfate and its subsequent opening. The formal synthesis of pancratistatin was accomplished in 14 steps (12 operations) from commercially available m-dibromobenzene. Experimental and spectral data are provided for all new compounds.

scholarly journals Toward the total synthesis of ritterazine N

2008 ◽  
Vol 80 (5) ◽  
pp. 1141-1148 ◽  
Author(s):  
Douglass F. Taber ◽  
Jean-Michel Joerger ◽  
Karen V. Taluskie
Keyword(s):  
Total Synthesis ◽  
Aldol Condensation ◽  
Side Chain ◽  
Tricyclic Core

Zr-mediated equilibrating cyclocarbonylation of a designed triene led with high diastereocontrol to the ABC 6-6-5 tricyclic core of ritterazine N. The 5-5 EF spiroketal side chain of ritterazine N was prepared by equilibrating cyclization of an acyclic keto diol. The two components were coupled, and the D ring was assembled by intramolecular aldol condensation.

scholarly journals The total synthesis of D-chalcose and its C-3 epimer

2013 ◽  
Vol 9 ◽  
pp. 2620-2624 ◽  
Author(s):  
Jun Sun ◽  
Song Fan ◽  
Zhan Wang ◽  
Guoning Zhang ◽  
Kai Bao ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Grignard Reaction ◽  
Efficient Synthesis ◽  
Camphorsulfonic Acid ◽  
Asymmetric Dihydroxylation ◽  
Key Steps ◽  
Stereogenic Center ◽  
Hydroxy Groups

We completed a new and efficient synthesis of D-chalcose (I) and the first synthesis of its C-3 epimer (I′) in nine steps with overall yields of 23% and 24%, respectively. The key steps in the sequence were the formation of the stereocenter on C3 via Grignard reaction, the introduction of the stereogenic center on C2 by Sharpless asymmetric dihydroxylation, the protection of the C1 and C2 hydroxy groups with tert-butyldimethylsilyl trifluoromethanesulfonate (TBSOTf), and the selective cleavage of the primary OTBS ether using catalytic DL-10-camphorsulfonic acid (CSA) in MeOH.

Total synthesis of zincophorin

2005 ◽  
Vol 77 (7) ◽  
pp. 1131-1137 ◽  
Author(s):  
Janine Cossy ◽  
Christophe Meyer ◽  
Magali Defosseux ◽  
Nicolas Blanchard
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Naturally Occurring ◽  
Key Steps ◽  
Stereogenic Center

A total synthesis of the naturally occurring ionophore zincophorin has been realized. The key steps are an intramolecular oxymercuration of a cyclopropanemethanol for the elaboration of the tetrahydropyran ring and a Carroll–Claisen rearrangement to control the configuration of the double bond at C20–C21 as well as the stereogenic center at C21.

Studies towards the Total Synthesis of Kadcotrione B

Synthesis ◽  
2019 ◽  
Vol 52 (05) ◽  
pp. 735-743
Author(s):  
Julakanti Satyanarayana Reddy ◽  
Marri Gangababu ◽  
Patel Manimala ◽  
Aluru Rammohan ◽  
Jillu Singh Yadav
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Side Chain ◽  
Wacker Oxidation ◽  
Efficient Approach ◽  
Salient Features ◽  
Robinson Annulation

A convergent and efficient approach towards the total synthesis of Kadcotrione B is described. For this purpose, the syntheses of two fragments, 6/6/5-fused tricyclic ring and C-9 side chain, were accomplished. The salient features of these syntheses are the utilization of aldol condensation, Evans aldol reaction, Horner–Wadsworth–Emmons olefination, Michael addition, Robinson annulation, and Wacker oxidation.

scholarly journals The Chemoenzymatic Total Synthesis of Phellodonic Acid, a Biologically Active and Highly Functionalized Hirsutane Derivative Isolated from the Tasmanian Fungus Phellodon melaleucus

2008 ◽  
Vol 61 (2) ◽  
pp. 94 ◽  
Author(s):  
Tristan A. Reekie ◽  
Kerrie A. B. Austin ◽  
Martin G. Banwell ◽  
Anthony C. Willis
Keyword(s):  
Total Synthesis ◽  
Cycloaddition Reaction ◽  
Genetically Engineered ◽  
Diels Alder ◽  
Biologically Active ◽  
Enantiomerically Pure ◽  
Toluene Dioxygenase ◽  
E Coli ◽  
Whole Cell Biotransformation ◽  
Genetically Engineered Microorganism

A total synthesis of the title natural product, 1, has been achieved using the cis-1,2-dihydrocatechol 7 as starting material. Compound 7 is readily obtained in large quantity and in an enantiomerically pure form through the whole-cell biotransformation of toluene using the genetically engineered microorganism E. coli JM109 (pDTG601) that overexpresses the enzyme toluene dioxygenase (TDO). Three key chemical steps were employed in the synthesis, the first of which was the microwave-promoted Diels–Alder cycloaddition reaction between diene 8 and cyclopent-1-en-2-one to give adduct 9. The second key step was the photochemically promoted oxa-di-π-methane rearrangement of the bicyclo[2.2.2]octenone derivative 15 of 9 to give the epimers 16 and 17, and the third key step was the reductive cleavage of the last pair of compounds so as to afford the linear triquinane 19. Elaboration of compound 19 to target 1 followed established procedures. Single-crystal X-ray analyses were carried out on compounds 11 and 19.

scholarly journals Chemoenzymatic Total Synthesis of (+)-10-Keto-Oxycodone from Phenethyl Acetate

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3477 ◽  
Author(s):  
Mary Endoma-Arias ◽  
Helen Dela Paz ◽  
Tomas Hudlicky
Keyword(s):  
Total Synthesis ◽  
Spectral Data ◽  
Heck Reaction ◽  
Recombinant Strain ◽  
Radical Cyclization ◽  
Benzylic Alcohol ◽  
Phenethyl Acetate ◽  
New Compounds ◽  
Intramolecular Heck Reaction ◽  
Absolute Stereochemistry

The total synthesis of (+)-10-keto-oxycodone was attained from phenethyl acetate in a stereoselective manner. Absolute stereochemistry was established via enzymatic dihydroxylation of phenethyl acetate with the recombinant strain JM109 (pDTG601A) that furnished the corresponding cis-cyclohexadienediol whose configuration corresponds to the absolute stereochemistry of the ring C of (+)-10-keto-oxycodone. Intramolecular Heck reaction was utilized to establish the quaternary carbon at C-13, along with the dibenzodihydrofuran functionality. The C-14 hydroxyl and C-10 ketone were installed via SmI2-mediated radical cyclization, and oxidation of a benzylic alcohol (obtained from an intermediate nitrate azide), respectively. The synthesis of (+)-10-keto-oxycodone was completed in a total of 14 operations (21 steps) and an overall yield of ~2%. Experimental and spectral data are provided for key intermediates and new compounds.

Total synthesis of (−)-exiguolide via an organosilane-based strategy

2015 ◽  
Vol 51 (40) ◽  
pp. 8484-8487 ◽  
Author(s):  
Hongze Li ◽  
Hengmu Xie ◽  
Zhigao Zhang ◽  
Yongjin Xu ◽  
Ji Lu ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Cross Coupling ◽  
Side Chain ◽  
Prins Cyclization ◽  
Key Steps

An organosilane-based strategy has been used to accomplish the total synthesis of (–)-exiguolide. The key steps involve: (1) geminal bis(silyl) Prins cyclization to construct the A ring; (2) silicon-protected RCM reaction to construct the macrocycle; and (3) Hiyama–Denmark cross-coupling to install the side chain.

Synthesis of (+/−) arthrographol

1991 ◽  
Vol 69 (12) ◽  
pp. 1909-1916 ◽  
Author(s):  
William A. Ayer ◽  
Peter A. Craw
Keyword(s):  
Total Synthesis ◽  
Key Words ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Single Step ◽  
Side Chain ◽  
Phenyl Sulfide ◽  
Blue Stain ◽  
Subsequent Elimination ◽  
Key Steps

A total synthesis of (+/−) arthrographol (1) in seven steps from vanillin is reported. Key steps in the synthesis are a single-step conversion of 5-allylvanillin (2) into the benzofuranmethanol 6, alkylation of the chloride 25 with the lithium anion of crotyl phenyl sulfide to give the sulfide 26, and formation of the 1(E),3(E)-1,3-pentadienyl side chain of arthrographol (1) via oxidation of the sulfide 26 and subsequent elimination of phenylsulfenic acid. The synthetic (+/−) arthrographol (1) inhibits the growth of Ophiostoma clavigerum (Robin.-Jeff. & Davids.) Harrington, the most pathogenic of the fungi associated with the blue stain disease of lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Key words: arthographol, alkylation, 2-butenyl phenyl sulfide, polyketide.

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