98524-12-0

Upstream product

• 123-38-6 propionaldehyde 
• 74-88-4 methyl iodide 
• 615-30-5 3-hydroxyl-2-methylpentanal 
• 535-11-5 Ethyl 2-bromopropionate 
• 121811-29-8 ethyl 2-methyl-3-oxopentanoate 
• 133181-02-9 3-hydroxy-2-methylene-pentanoic acid methyl ester 
• 802294-64-0 propionic acid 
• 81818-94-2 2',6'-bis(1,1-dimethylethyl)-4'-methoxyphenyl (2SR,3SR)-2-methyl-3-hydroxyopentanoate 
• 1589-07-7 (3S^*,4R^*)-4-hydroxy-3-methylhexene 
• 131793-60-7 N-<(2S,3R)-3-hydroxy-2-methylpentanoyl>-(1R,2S,6R,7S)-1,10,10-trimethyl-4-oxo-5-aza-3-oxatricyclo<5.2.1.0^2,6>decane 
• 119460-80-9 (4SR,5SR)-2,5-dihydroxy-2,4-dimethyl-2-O-trimethylsilylheptan-3-one 
• 1538-21-2 (3R^*,4R^*)-4-hydroxy-3-methylhexene 
• 137033-02-4 (+/-)-3-hydroxy-2-methylenepentanoic acid 

Downstream Products

• 114607-20-4 1-ethylpropyl (2SR,3RS)-3-hydroxy-2-methylpentanoate 
• 96-22-0 pentan-3-one 
• 115367-79-8 4-Ethyl-3-methyl-oxetan-2-one 
• 5145-01-7 3,5-dimethyldihydrofuran-2-one 
• 114607-20-4 2-Methyl-3-hydroxypentanoic acid threo-3-pentyl ester 
• 105-43-1 3-methylvaleric acid 

Relevant academic research and scientific papers

CHIRAL PROPIONATE ENOLATE EQUIVALENTS FOR THE STEREOSELECTIVE SYNTHESIS OF THREO- OR ERYTHRO-α-METHYL-β-HYDROXY ACIDS.

The aluminium and copper enolates derived from (n5-C5H5)Fe(CO)(PPh3)COCH2CH3 are chiral propionate enolate equivalents which on reaction with aldehydes (RCHO, R=Me, Et, iPr, tBu) provide stereoselective sytheses of threo-

New synthesis of (±)-sitophilate using carboxylic acid dianion methodology - A stereoselectivity study

A simple two-step synthesis of (±)-sitophilate in has been developed by addition of propanal to the lithium enediolate of propanoic acid and subsequent esterification with 3-pentanol under standard Fischer conditions. Efforts to control the diastereoselectiv-ity to generate the syn isomer are described. A modest degree of asymmetric induction is found using chiral amides as base. Georg Thieme Verlag Stuttgart.

Diastereoselectivity in heterogeneous catalytic hydrogenation of Baylis-Hillman adducts. Total synthesis of (±)-sitophilate

We describe herein a highly diastereoselective total synthesis of racemic sitophilate, based on the results obtained in a diastereoselective heterogeneous catalytic hydrogenation reaction of a set of Baylis-Hillman adducts originating from aliphatic aldehydes.

Asymmetric aldol reactions. A new camphor-derived chiral auxiliary giving highly stereoselective aldol reactions of both lithium and titanium(IV) enolates

A new, conformationally rigid camphor-derived N-propionyloxazolidinone effects asymmetric stereochemical control in syn-selective aldol condensations of the derived lithium and titanium(IV) enolates with a variety of aldehydes. Simple and diastereofacial selectivities of the reaction are high, and diastereomeric purities of the crude aldol adducts can be improved, usually by a single recrystallization, to levels of 98-99% in most cases. The observed facial selectivity is best explained by a transition structure in which intramolecular chelation between the oxazolidinone carbonyl oxygen and the metal induces an enolate π-facial differentiation; the major products observed are those expected from chelation control. Hydrolysis of the exocyclic carbonyl of the aldol adducts led to β-hydroxy-α-methylcarboxylic acids, with recovery of the chiral auxiliary. Consonant double-asymmetric induction with (R)-2-(benzyloxy)propanal gave the product expected from oxazolidinone chelation but nonchelation of the aldehyde benzyloxy group.

A VERSATILE SYNTHESIS OF 3-SUBSTITUTED 5-ALKYL BUTYROLACTONES VIA DYOTROPIC REARRANGEMENT

Substituted acetic acid dianions are convertable to 3,5-disubstituted butyrolactones, employing a dyotropic rearrangement as the key step.

Chiral Acetate Enolate Equivalent for the Synthesis of β-Hydroxy Acids

The aluminium enolate derived from (η5-C5H5)Fe(CO)(PPh3)(COMe) undergoes stereoselective aldol condensations with aldehydes to generate β-hydroxy acyl complexes which yield β-hydroxy acids on decomplexation.

ERYTHROSELECTIVITY IN ADDITION OF γ-SUBSTITUTED ALLYLSILANES TO ALDEHYDES IN THE PRESENCE OF TITANIUM CHLORIDE

(E)-Crotyltrimethylsilane and (E)-cinnamyltrimethylsilane were allowed to react with aldehydes (RCHO: t-Bu, i-Pr, Et, Me) in the presence of titanium chloride to give erythro homoallyl alcohols with over 93percent selectivity.Lower erythroselectivity was observed in the reaction of (Z)-allylsilanes.

ACYCLIC STEREOSELECTION-13; ARYL ESTERS: REAGENTS FOR THREO-ALDOLIZATION

Preformed Li enolates of hindered aryl esters condense with aldehydes to give predominantly threo aldols.The method has been explored with esters 3 (DMP propionate), 4 (BHT propionate), 5 (DBHA propionate).DMP propionate reacts with benzaldehyde and α-unbranched aliphatic aldehydes to give threo:erythro ratios of about 6.5:1.However, with α-branched aliphatic aldehydes, ester 3 gives only threo-aldols.BHT propionate and DBHA propionate give only threo-aldols with all aldehydes studied.The DMP aldols may be converted into β-hydroxy acids by simple hydrolysis with KOH in aqueous methanol.BHT aldols cannot be hydrolyzed without retroaldolization.However, these aldols can be reduced to diastereomerically pure 1,3-diols.The DBHA aldols can converted into β-hydroxy acids by a method involving oxidation with ceric ammonium nitrate (CAN) in aqueous acetonitrile.Threo-selectivity is also seen in the condensations of DMP butyrate (15), DBHA butyrate (16), DMP pentenoate (17), and BHT pentenoate (18).The approach has been utilized in a stereoselective synthesis of racemic methyl corynomycolate.