Highly stereoselective synthesis of antitumor agents: both enantiomers of goniothales diol,altholactone, and isoaltholactone

A flexible stereoselective route to synthesize both enantiomers of the highly functionalized substituted tetrahydrofurans and α,β-unsaturated-δ-lactones, goniothales diol, altholactone, and isoaltholactone, from readily available cinnamyl alcohol is described. This approach derived its asymmetry from Sharpless catalytic asymmetric epoxidation and Sharpless asymmetric dihydroxylation reactions. The resulting diols were produced in high enantiomeric excess and were cyclized in a stereoselective manner in the presence of a catalytic amount of camphor sulfonic acid.     

The first stereoselective and the total synthesis of Leiocarpin C and total synthesis of (+)-Goniodiol

The synthesis of the styryl lactone Leiocarpin C has been achieved in a highly stereoselective manner using Jacobsen’s kinetic resolution, Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation as key steps. This is the first total synthesis of Leiocarpin C, and thus establishes for the first time the absolute stereochemistry of this natural product.     

Stereoselective Synthesis of Tetrahydropyran D-Ring of Methyl Sartortuoate

A stereoselective synthesis of functionalized tetrahydropyran D‐ring of methyl sartortuoate ( 1 ) was achieved starting from geraniol in a high yield. Sharpless asymmetric kinetic resolution, asymmetric dihydroxylation as well as asymmetric epoxidation were applied as key steps to establish all the four stereocenters of the D‐ring.     

Alternative total synthesis of (+)-aspicilin

The total synthesis of an 18-membered polyhydroxylated macrolide (+)-Aspicilin was accomplished starting from commercially available enantiopure propylene oxide and D-(+)-gluconolactone by asymmetric synthetic approach. The key reactions involved are Witttig reaction, Sharpless asymmetric dihydroxylation, and Yamaguchi macrolactonization.     

First stereoselective total synthesis of antibiotic macrolide Berkeleylactone F

The first stereoselective total synthesis of antibiotic macrolide Berkeleylactone F is described. The synthetic sequence notably features Sharpless kinetic resolution to access chiral epoxide followed by its regioselective ring-opening reaction, Sharpless asymmetric reaction and ring-closing metathesis.     

An efficient approach for the total synthesis of balticolid

An efficient stereoselective total synthesis of balticolid has been accomplished starting from known aldehyde. The key steps involved in this synthesis are Sharpless asymmetric epoxidation, Wittig olefination, alkylation of 1,3-dithiane and Yamaguchi macrolactonization.     

Stereoselective synthesis of (+)-radicamine B

A simple and efficient stereoselective synthesis of naturally occurring pyrrolidine alkaloid, radicamine B has been accomplished in 13 steps from the commercially available starting materials with an overall yield of 9.75%. The synthesis utilizes Sharpless asymmetric epoxidation and Horner-Wadsworth-Emmons (HWE) olefination as key steps.     

Stereoselective synthesis of the C33-C44 fragment of palau’amide

An efficient stereoselective synthesis of the C33-C44 fragment of palau’amide is described using a Sharpless asymmetric epoxidation, a regioselective nucleophilic ring opening of the epoxide, a Grignard reaction and a Luche stereoselective reduction of a keto compound as the key steps.     

Stereoselective total synthesis of oplopandiol,oploxyne A,and oploxyne B

A stereoselective total synthesis of oplopandiol, oploxyne A, and (−)-oploxyne B is described. The key reactions include Sharpless asymmetric epoxidation, d-proline catalyzed aminoxylation, Cadiot–Chodkiewicz cross-coupling reaction, m-CPBA induced substrate-controlled stereoselective epoxidation, and Lewis acid catalyzed stereo- and regioselective ring-opening of epoxide.     

The Stereoselective Formal Synthesis of (-)-Slaframine

(-)-Slaframinel,anindolizidincalkal()idisolatedtYomthcfungusR/7i~()c't())IicllegIInlinicolainl965',usuallyinItctsleguminouscattle1tcdsandisrcsponsiblcli>rexcessivesalivationintheanimals.Also,lshowsthep()tcntialityinthetreatmentofdiseasesinvolvingcholinergenicdysfunction,andevenhassomebcneficialeffcctsonruminantdigestivefunction.Muchattentionhasbecndevotedtoitssynthesis'sinccitsabs()lutcstere()chcmistrywasestablishedas(lS,6S,8aS)-l-acetoxy-6-an1in()-ind()lizidine'.Thefirstenantioselectiveto…     

Enantio- and diastereocontrolled total synthesis of (+)-boronolide

An efficient stereoselective total synthesis of (+)-boronolide from valeraldehyde is described. The key steps include a Sharpless asymmetric hydroxylation, a chelation-controlled vinyl Grignard reaction followed by a Sharpless asymmetric epoxidation, hydrolytic kinetic resolution, and a ring-closing metathesis.     

Stereoselective Synthesis of (+)-Nephrosteranic Acid by Ring-Closing Metathesis and Its Biological Evaluation

A simple and efficient approach to (+)-nephrosteranic acid from dodecanol as a starting material is described, employing Sharpless asymmetric epoxidation, ring-closing metathesis, and Gilman addition of a vinyl group as key steps. These key reactions allow fast access to trisubstituted γ-butyrolactone. The molecule synthesized exhibits potent antifungal, antibacterial, and cytotoxic activities against all the tested strains.     

Stereoselective synthesis of C1-C9 and C9-C17 fragments of (+)-13-deoxytedanolide

An efficient and highly stereoselective asymmetric synthesis of C1-C9 and C9-C17 fragments of (+)-13-deoxytedanolide have been achieved. Utilization of desymmetrization technique to prepare the triol with five stereogenic centers, regioselective Sharpless asymmetric dihydroxylation, Evans' aldol reaction, chiral methylation, and Wittig olefination are highlights of the synthesis.     

Formal total synthesis of borrelidin: synthesis of C1-C11 fragment via desymmetrization strategy

A stereoselective formal total synthesis of borrelidin is described. The synthetic strategy for synthesis of C1-C11 fragment features desymmetrization of Diels-Alder adduct, Sharpless asymmetric epoxidation, regioselective opening of chiral epoxide, and alkylation using Evans chiral auxiliary.     

Convergent and Stereoselective Synthesis of Sarcophytol-Q Precursor: (11S)-3,7,11,15-Tetramethyl-11-hydroxy-14-oxo-3E,7E,12E-hexadecatrienal

A chiral precursor of sarcophytol-Q, (11S)-3,7,11,15-tetramethyl-11-hydroxy-14-oxo-3E,7E,12E-hexadecatrienal, was synthesized in a convergent and stereoselective manner starting from geraniol and 4-hydroxy-2-butanone in nine steps. The key steps were asymmetric Sharpless epoxidation, base-induced dehydrohalogenation rearrangement of chiral epoxy chloride 5 and the phase transfer catalytic coupling reaction of allylic phenyl sulfone 4 with chiral allylic chloride 3 .     

First stereoselective total synthesis of decytospolides A and B

The first stereoselective total synthesis of decytospolides A and B has been accomplished starting from n-hexanal. The key steps involved in this synthesis are Horner-Wittig reaction, Sharpless asymmetric epoxidation, and oxa-Michael reaction.     

First total synthesis of parvistone C and its C8-epimer

Diastereoselective first total synthesis of parvistone C 1 and C8-epimer 1a are described. The key features of our synthesis include Sharpless asymmetric dihydroxylation, stereoselective aryl Grignard reactions, Still–Gennari olefination, and intramolecular cyclization.     

Progress towards the total synthesis of 2,3-dihydroxytrinervitanes

Intramolecular Diels-Alder approach to construct the fused AB ring of trinervitane has been demonstrated efficiently. The key intermediate for the Diels-Alder cyclization has been achieved following highly stereoselective Julia-Kocienski olefination, Sharpless epoxidation and Evan’s asymmetric alkylation as the key reactions.     

Asymmetric dihydroxylation of vinyl sulfones: routes to enantioenriched α-hydroxyaldehydes and the enantioselective syntheses of furan-2(5H)-ones

The asymmetric dihydroxylation of α,β-unsaturated sulfones under Sharpless conditions affords enantioenriched α-hydroxyaldehydes in a complex mixture of dimeric species. These mixtures undergo olefination generating the corresponding α,β-unsaturated esters or furan-2(5H)-ones with high levels of enantiomeric excess. The application of this method for the rapid stereoselective synthesis of the furanone natural products; quercus lactone and maritolide, are described.     

Stereoselective synthesis of 5′-hydroxyzearalenone

A first stereoselective total synthesis of 14-memebered β-resorcylic macrolactone 5′-hydroxyzearalenone (1) has been achieved. The key steps are Jocobsen hydrolytic kinetic resolution, Sharpless asymmetric dihydroxylation, Vilsmeier-Haack reaction, Mitsunobu esterification and ring-closing metathesis.