32475-72-2

Upstream product

• 4295-92-5 (3R,5S)-3,5-dimethyldihydro-2H-pyran-2,6(3H)-dione 
• 2121-69-9 (2R,4S)-2,4-dimethylpentane-1,5-diol 
• 16958-19-3 (2E)-2-methyl-2-penten-1-ol 
• 201230-82-2 carbon monoxide 
• 92340-69-7 C₇H₁₄O₂ 

Downstream Products

• 130288-43-6 (2S,4R)-5-(tert-Butyl-dimethyl-silanyloxy)-2,4-dimethyl-pentanoic acid (1-phenyl-ethyl)-amide 
• 130288-43-6 (2R,4S)-5-(tert-Butyl-dimethyl-silanyloxy)-2,4-dimethyl-pentanoic acid (1-phenyl-ethyl)-amide 
• 130288-43-6 (2S,4R)-5-(tert-Butyl-dimethyl-silanyloxy)-2,4-dimethyl-pentanoic acid ((R)-1-phenyl-ethyl)-amide 
• 331942-70-2 ((2S,4R)-5-Hydroxy-2,4-dimethyl-pentyl)-((R)-1-phenyl-ethyl)-carbamic acid tert-butyl ester 
• 331942-63-3 {(3R,5S)-6-[tert-Butoxycarbonyl-((R)-1-phenyl-ethyl)-amino]-3,5-dimethyl-2-oxo-hexyl}-phosphonic acid dimethyl ester 
• 331942-61-1 [(E)-(2S,4R,8R,9S,11R)-8-(tert-Butyl-dimethyl-silanyloxy)-9-hydroxy-2,4,11,15-tetramethyl-5,13-dioxo-hexadeca-6,15-dienyl]-((R)-1-phenyl-ethyl)-carbamic acid tert-butyl ester 
• 331942-72-4 [(E)-(2S,4R,8R,9S,11R)-8-(tert-Butyl-dimethyl-silanyloxy)-9-(4-methoxy-benzyloxy)-2,4,11-trimethyl-5,13-dioxo-tridec-6-enyl]-((R)-1-phenyl-ethyl)-carbamic acid tert-butyl ester 
• 331942-71-3 [(E)-(2S,4R,8R,9S,11S)-8,13-Bis-(tert-butyl-dimethyl-silanyloxy)-9-(4-methoxy-benzyloxy)-2,4,11-trimethyl-5-oxo-tridec-6-enyl]-((R)-1-phenyl-ethyl)-carbamic acid tert-butyl ester 
• 75658-88-7 (+)-(2S,4R)-cis-2,4-dimethyl-δ-valerolactone 
• 130288-45-8 Benzoic acid (E)-(2R,4S)-6-methoxy-2,4-dimethyl-hex-5-enyl ester 
• 74034-73-4 (3R,5S)-3,5-dimethyltetrahydro-2H-pyran-2-one 
• 130288-46-9 Benzoic acid (2R,4S)-2,4-dimethyl-6-oxo-hexyl ester 
• 130304-59-5 Benzoic acid (6E,8E)-(2R,4R,10R)-2,4,8,10-tetramethyl-dodeca-6,8-dienyl ester 

Relevant academic research and scientific papers

Intramolecular stereoselective protonation of aldehyde-derived enolates

Picking sides: Asymmetric protonation of the titled compounds poses a most significant challenge and has been addressed by taking advantage of internal protonation and subsequent hemiacetal formation to avoid epimerization (see scheme). The substrates employed in these transformations can be easily accessed through a sequence of vinylogous aldol reactions with subsequent conjugate reductions.

Remote control of regio- and diastereoselectivity in the hydroformylation of bishomoallylic alcohols with catalytic amounts of a reversibly bound directing group

(Figure Presented) Remote and reversible! Phosphinites serve as reversibly bound directing groups for the remote control of the regio- and diastereoselective hydroformylation of bishomoallylic alcohols (see scheme; r.r: regioisomer ratio). The distance between the double bond and the functional hydroxy group to which the directing group is reversibly bound is the longest ever reported.

Total Synthesis of rapamycin

For over 30 years, rapamycin has generated a sustained and intense interest from the scientific community as a result of its exceptional pharmacological properties and challenging structural features. In addition to its well known therapeutic value as a potent immunosuppressive agent, rapamycin and its derivatives have recently gained prominence for the treatment of a wide variety of other human malignancies. Herein we disclose full details of our extensive investigation into the synthesis of rapamycin that culminated in a new and convergent preparation featuring a macro-etherification/catechol-templating strategy for construction of the macrocyclic core of this natural product.

The First Stereoselective Palladium-Catalyzed Cyclocarbonylation of β,γ-Substituted Allylic Alcohols

β,γ-Substituted allylic alcohols react with CO in the presence of catalytic quantities of palladium acetate and 1,4-bis(diphenylphosphino)butane affording α,β-substituted-γ-butyrolactones in 42-85% isolated yields. The complete stereoselectivity observed

Macrocyclic Pyrrolizidine Alkakoid Analogues. Synthesis and Stereochemistry of (12R,14S)-and (12S,14R)-12,14-Dimethyl-1,2-didehydrocrotalanine. X-Ray Molecular Structure of the (12S,14R)-Isomer

Treatment of (+)-retronecine (1) with meso-2,4-dimethylglutaric anhydride followed by lactonisation via the pyridine-2-thiol esters yielded (12R,14S)-(3) and (12S,14R)-dimethyl-1,2-didehydrocrotalanine (4).These pyrrolizidine alkaloid analogues were separated by column chromatography.The absolute configuration of the acid portion of each analogue was established by a seguence of two chemoselective reactions to afford optically active tetrahydro-3,5-dimethyl-2H-pyran-2-one.An X-ray crystal structure analysis confirmed the structure and stereochemistry of the (12S,14R)-isomer (4).The ester carbonyl groups of compound (4) are synparallel and directed below the plane of the macrocyclic ring.

ENZYMES IN ORGANIC SYNTHESIS-29. PREPARATIONS OF ENANTIOMERICALLY PURE cis-2,3- AND 2,4-DIMETHYL LACTONES VIA HORSE LIVER ALCOHOL DEHYDROGENASE-CATALYZED OXIDATIONS

Further examples of the broad applicability of horse liver alcohol dehydrogenase-catalyzed oxidations of meso-diols as a route to chiral lactones of asymmetric synthetic value are described.The acyclic meso substrates, cis-2,3-dimethyl- and -diethylbutane-1,4-diols, and cis-2,4-dimethylpentane-1,5-diol, are stereospecifically oxidized in good yields to the corresponding enantiomerically pure γ- and δ-lactones.The oxidation of cis-3,4-bis(hydroxymethyl)thiacyclopentane is similarly stereospecific.For each meso-diol the oxidation takes place with a net stereospecifity for the hydroxymethyl groups attached to the S-centers, with the initially formed hydroxyaldehydes undergoing further enzyme-catalyzed oxidations via their hemiacetal forms to produce lactone products directly.