112897-04-8

Upstream product

• 95514-03-7 (R)-methyl 3-(tert-butyl(diphenyl)silyloxy)-2-methylpropanoate 
• 72657-23-9 methyl (R)-3-hydroxy-2-methylpropionate 
• 58479-61-1 tert-butylchlorodiphenylsilane 
• 131979-99-2 (S)-3-acetoxy-1-(tert-butyldiphenylsiloxy)-2-methylpropane 
• 33729-92-9 tert-butyldiphenylsilane 
• 1036278-68-8 C₂₃H₃₄O₃Si 
• 95514-04-8 (S)-3-(tert-butyldiphenylsilyloxy)-2-methylpropan-1-ol 

Downstream Products

• 142592-66-3 ethyl (2E,4S)-5-(tert-butyldiphenylsilyloxy)-2,4-dimethylpent-2-enoate 
• 251353-52-3 5-(tert-butyl-diphenyl-silanyloxy)-4-methyl-pent-1-en-3-ol 
• 337375-93-6 (S)-tert-butyl((2-methylbut-3-yn-1-yl)oxy)diphenylsilane 
• 732247-32-4 (2S,4S,5R,6R)-2-Benzyloxy-7-(tert-butyl-diphenyl-silanyloxy)-5-hydroxy-4,6-dimethyl-heptan-3-one 
• 891197-96-9 (+)-(2R,3S,4S)-1-(tert-butyldiphenylsilanyloxy)-4-methoxy-2-methylhex-5-en-3-ol 
• 891197-97-0 (-)-(2R,3S,4R)-1-(tert-butyldiphenylsilanyloxy)-4-methoxy-2-methylhex-5-en-3-ol 
• 891197-98-1 (+)-(2R,3R,4S)-1-(tert-butyldiphenylsilanyloxy)-4-methoxy-2-methylhex-5-en-3-ol 
• 906671-11-2 5-(tert-butyl-diphenyl-silanyloxy)-4-methyl-2-oxo-pentanoic acid methyl ester 
• 198124-61-7 (3R,4R,5R)-3,5-dimethyl-6-[tert-butyldiphenylsilyloxy]-hex-1-en-4-ol 
• 320575-05-1 (2S,3R)-4-(tert-butyldiphenylsiloxy)-2-(methoxymethoxy)-3-methyl-1-butanal 
• 320575-07-3 (2S,3R)-4-(tert-Butyl-diphenyl-silanyloxy)-2-hydroxy-3-methyl-butyric acid methyl ester 
• 623938-88-5 (2R,3S,4S,6S)-4-benzyloxy-7-(tert-butyldiphenylsiloxy)-2,6-dimethyl-5-methoxymethoxyheptanal 
• 718629-10-8 (2S,3R)-4-(tert-Butyl-diphenyl-silanyloxy)-2-methoxymethoxy-3-methyl-butyric acid methyl ester 

Relevant academic research and scientific papers

Ring-closing metathesis approaches towards the total synthesis of rhizoxins

Efforts are described towards the total synthesis of the bacterial macrolide rhizoxin F, which is a potent tubulin assembly and cancer cell growth inhibitor. A significant amount of work was expanded on the construction of the rhizoxin core macrocycle by ring-closing olefin metathesis (RCM) between C(9) and C(10), either directly or by using relay substrates, but in no case was ringclosure achieved. Macrocycle formation was possible by ring-closing alkyne metathesis (RCAM) at the C(9)/C(10) site. The requisite diyne was obtained from advanced intermediates that had been prepared as part of the synthesis of the RCM substrates. While the direct conversion of the triple bond formed in the ring-closing step into the C(9)-C(10) E double bond of the rhizoxin macrocycle proved to be elusive, the corresponding Z isomer was accessible with high selectivity by reductive decomplexation of the biscobalt hexacarbonyl complex of the triple bond with ethylpiperidinium hypophosphite. Radical-induced double bond isomerization, full elaboration of the C(15) side chain, and directed epoxidation of the C(11)-C(12) double bond completed the total synthesis of rhizoxin F.

Quinocidin, acytotoxic antibiotic with anunusual 3,4-dihydroquinolizinium ring and michael acceptor reactivity toward thiols

Cytotoxicity-guided fractionation of the culture broth of Actinomadura sp. TP-A0019 led to the isolation of quinocidin (1), acytotoxic antibiotic with an unusual 3,4-dihydroquinolizinium ring. The structural assignment was made on the basis of high-field NMR experiments and chemical synthesis. Comparison ofthe spectral properties of 1 with those of its synthetic counterparts revealed that 1 is aracemic mixture of two enantiomers, which showed similar cytotoxicity against HeLa-S3 cells. Nucleophile-trap-ping experiments demonstrated that 1 captured 2-mer-captoethanol and N-acetyl-l-cysteine by means of aMi-chael addition-type reaction, but was inert toward 2-ami-noethanol and glycolic acid. Notably, the addition of 1 to thiols proceeded smoothly in neutral aqueous media at room temperature. In view of the thiol-trapping ability and the unusual structure, 1 provides aunique scaffold for designing drug leads and protein-labeling probes.

(R)-N-(1-Methyl-2-hydroxyethyl)-13-(S)-methyl-arachidonamide (AMG315): A Novel Chiral Potent Endocannabinoid Ligand with Stability to Metabolizing Enzymes

The synthesis of potent metabolically stable endocannabinoids is challenging. Here we report a chiral arachidonoyl ethanolamide (AEA) analogue, namely, (13S,1′R)-dimethylanandamide (AMG315, 3a), a high affinity ligand for the CB1 receptor (Ki o

Syntheses of Gymnothespirolignans B and C and Non-natural Isomer 9-Epi-gymnothespirolignan B

Syntheses of polycyclic spiro lignans gymnothespirolignans B and C as well as the unnatural isomer 9-epi-gymnothespirolignan B were accomplished using (R)-Roche ester and an appropriately substituted fluorenone. Key features of the convergent syntheses include coupling of the fluorenone and an iodo-alkene intermediate derived from (R)-Roche ester in the presence of the Lewis acid TiCl(OiPr)3, C9-O bond formation via an SN2 reaction with retention of stereochemistry, and diastereoselective hydrogenations of a common alkene intermediate guided by accessibility or positioning by the C8-methoxy.

Identification and Total Synthesis of an Unstable Anticancer Macrolide Presaccharothriolide Z Produced by Saccharothrix sp. A1506

Saccharothriolides A-F are 10-membered microbial macrolides proposed to be generated from their precursors presaccharothriolides X-Z. Previously, we isolated presaccharothriolide X, and its unique natural prodrug-like properties have intrigued us. However

Polyoxygenated Tertiary Alcohols: A Kiyooka Approach

A Kiyooka aldol approach for the stereoselective synthesis of tertiary alcohols is presented. This approach allows for the incorporation of different substituents at all three remaining positions at the chiral center bearing the tertiary alcohol. To demon

Stereoselective synthesis of the C3-C15 fragment of callyspongiolide

The synthesis of C3-C15 fragment of callyspongiolide, a 14-membered macrolides isolated from the marine sponge Callyspongia sp., which was collected from the Indonesia, is reported. Highlights of the synthesis include construction of E-olefin through Juli

Stereospecific Allylic Functionalization: The Reactions of Allylboronate Complexes with Electrophiles

Allylboronic esters react readily with carbonyls and imines (π-electrophiles), but are unreactive toward a range of other electrophiles. By addition of an aryllithium, the corresponding allylboronate complexes display enhanced nucleophilicity, enabling addition to a range of electrophiles (tropylium, benzodithiolylium, activated pyridines, Eschenmoser's salt, Togni's reagent, Selectfluor, diisopropyl azodicarboxylate (DIAD), MeSX) in high regio- and stereocontrol. This protocol provides access to key new functionalities, including quaternary stereogenic centers bearing moieties such as fluorine and the trifluoromethyl group. The allylboronate complexes were determined to be 7 to 10 orders of magnitude more reactive than the parent boronic ester.

Asymmetric total synthesis of (-)-rasfonin

An efficient chemoenzymatic asymmetric synthesis of pyranone containing natural product (-)-rasfonin is presented here. Enantioselective enzymatic desymmetrization (EED) and a unique Gluconobacter oxydans mediated oxidative kinetic resolution (OKR) have been successfully employed to install three stereocenters (C6′, C7, and C9) of the target molecule. Stereoselective Achmatowicz reaction of a properly decorated furyl nucleus led to the core pyranone structure of rasfonin. At the late stage of the synthesis Negishi coupling has been used to complete the synthesis.

PROCESS FOR PREPARATION OF (3R)-2,4-DI-LEAVING GROUP-3-METHYLBUT-1-ENE

The specification relates to compounds and process for the preparation of a compound of formula 7, where LG is a leaving group and hal is a halide and is Cl, Br or I. The compound of formula 7 can be useful in the preparation of natural products, such as