90211-82-8

Upstream product

• 106948-09-8 (R)-3,3-dimethyloxiranemethanol 4-methylbenzenesulfonate 
• 204686-66-8 methyl (2S)-3-methyl-2-(tetrahydro-2H-pyran-2-yloxy)butanoate 
• 204686-67-9 (2S)-3-methyl-2-(tetrahydropyran-2-yloxy)butan-1-ol 
• 204686-71-5 (S)-2-Isopropyl-1,4-dioxa-spiro[4.5]decane 
• 24347-63-5 methyl (S)-2-hydroxy-3-methylbutanoate 
• 17407-55-5 (S)-2-Hydroxy-3-methylbutanoic acid 
• 72-18-4 L-valine 
• 204686-68-0 Toluene-4-sulfonic acid (S)-3-methyl-2-(tetrahydro-pyran-2-yloxy)-butyl ester 
• 24347-56-6 (S)-3-methylbutane-1,2-diol 
• 98-59-9 p-toluenesulfonyl chloride 

Downstream Products

• 129972-71-0 Toluene-4-sulfonic acid (S)-2-methoxymethoxy-3-methyl-butyl ester 
• 55123-01-8 (S)-(+)-1,2-epoxy-3-methylbutane 
• 129972-63-0 <(2S)-2-(methoxymethyloxy)-3-methylbutyl>diphenylphosphine 
• 27460-26-0 24(R)-Hydroxycholesterol 
• 90211-85-1 (24R)-6β-methoxy-22-phenylsulfonyl-24-hydroxy-3α,5α-cyclocholestane 

Relevant academic research and scientific papers

Enantioselective Synthesis and Absolute Configuration of (R)-(+)-Lunacridine and (S)-(+)-Lunacrine

(R)-(-)-Lunacridine 1 has been synthesized in 97.3percent e.e. using a chiron approach through L-valine and D-mannitol as the starting compounds to corroborate its absolute configuration.The key intermediate (S)-1,2-epoxy-3-methylbutane 11 was synthesized from (L)-valine (3 -> -> 11) and a (D)-mannitol derivative (12 -> -> 11) via functional group manipulation.The epoxide 11 was reacted with lithiated 2,4,8-trimethoxyquinoline 17 and the resulting product 18 was selectively deprotected at the 2-position followed by N-methylation of 19 to give 1.In an alternative strategy 11 was transformed into the THP-acid 23 through the chiral lactone 20.Condensation of 23 with substituted methyl anthranilate gave the amide 24 which on cyclisation, methylation and deprotection steps sequentially afforded 1.

Stereoselective Synthesis of Squalamine Dessulfate

Squalamine dessulfate (24R) and the unnatural product squalamine dessulfate (24S) have been synthesized from stigmasterol.The key step is establishing the C24 stereochemistry is attachment of the sidechain at C22 using either (2R)- or (2S)-1,2-epoxy-3-met

Synthesis of (β-N-sulfonylaminoalkyl)phosphines and their use in palladium-mediated asymmetric synthesis

A series of (β-N-sulfonylaminoalkyl)phosphine ligands has been developed and employed for asymmetric palladium-catalyzed hydrosilylation and Heck-type hydroarylation, affording up to 72% ee and 90% yield.

Chemoselective reduction of 2,3-epoxy tosylates with DIBAL-H as a general route to enantiomerically-enriched 1-tosyloxy-2-alkanols

2,3-Epoxy tosylates may be reduced with DIBAL-H in CH2Cl2 or ether at -40°C to 1-tosyloxy-2-alkanols in high (94-98%) yields.

Asymmetric Hydrosilylation of Cyclopentadiene and Styrene with Chlorosilanes Catalyzed by Palladium Complexes of Chiral (β-N-Sulfonylaminoalkyl)phosphines

It was found that the palladium complexes of newly prepared chiral (β-aminoalkyl)phosphine derivatives bearing N-sulfonyl groups were efficient catalysts for asymmetric hydrosilylations of cyclopentadiene and styrene with chlorosilanes.

A Stereoselective Synthesis and a Convenient Synthesis of Optically Pure (24 R)- and (24 S)-24-hydroxycholesterols

A new stereoselective synthesis of optically pure (24 S)-24-hydroxycholesterol (cerebrosterol) and (24 R)-24-hydroxycholesterol, using D- and L-valines as chiral sources, as well as a convenient synthesis, are described.