Hydroxy adds acylation with

R = R = H, R = OCH2CH2OH), and the hydroxy group then was acylated with 2-(dimethylamino)acetic add in CH2CI2 in the presence of 1,3-dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine at room temperature (94EUP626378, 95USP5378720). 

Synonyms Cocamidopropyl phosphatidyl PG-dimonium chloride Phosphoric add, triester with N-(2,3-dihydroxypropyl)-N,N-dimethyl-3-[(1-oxococo-alkyl) amino-1-propanaminium chloride 1-Propanaminium, 3,3, 3"-[phosphinylidyne-tris(oxy)]tris[n-(3-aminopropyl) -2-hydroxy-n,n-dimethyl-, n,n, n"-tri-c6-18 acyl derivs. trichlorides... 

Chiral acyliminiums were used for the preparation of enantiopure piperidines [267]. Recently, the use of enantio-enriched y-alkoxyallyltins onto chiral acyl iminiums [268] provided a new entry into the synthesis of potential precursors of a-amino-/3-hydroxy adds or aminosugars, with a total control of the stereochemistry. 

The antibiotic viscosin from Pseudomonas viscosa (Scheme 8) is a cyclo-depsipeptide acyl-ated at the N-terminus with D-3-hydroxydecanoic add.[103 112] The C-terminal carboxy group is esterified with the hydroxy group of the Thr3 residue. The synthesis of this natural product presents the problem of an ester ring closure and was performed in two steps with initial solid-phase synthesis of the Thr3-0-branched linear intermediate followed by ring closure with formation of the amide bond.1 131... 

Despite this versatility, cyanide adds only one carbon atom of course and we need other more general acyl anion equivalents. In chapter 16 we saw how acetylenes can give rise to ketones by hydration. A very simple example is the hydroxy-ketone 11 that could come from the acetylenic alcohol 12 by hydration and hence from acetone with the anion of acetylene acting as the acyl anion equivalent. 

Deracemization of mandelic add with the combined action of two enzymes has been reported. rac-MandeUc acid is acylated by a Pseudomonas sp. lipase in diisopropyl ether. After solvent removal the mfacture of mandeUc acid enriched in the R-form and the 0-acetyl derivative of the S-configuration are subjected to the mandelate racemase-catalyzed racemization in aqueous buffer. In these conditions only the non-acetylated hydroxy acid is racemized. In order to obtain (S)-0-acetylmandelic acid in an 80% isolated yield and a >98% e.e. the process must be repeated four times [9]. 

Cottjugate addition of water. The a,0 unsaturated acyl CoA produced in step 1 reacts with water by a conjugate addition pathway Spction 19.M) to yk ld a fJ-hydroxy acyl CoA in a process catalyzed by the enzyme eftoyl CoA hydratose. Water as nucleophile add to fi carbon of the douUe bond, yielding an enolate ion intermediate, whi[Pg.1198]

Classically, the acylzirconocene chlorides can be converted into aldehydes, carboxyhc acids, esters, and acyl halides. Recently, the usefulness of acylzirconocenes has been extended. In fact, these unmasked acyl anions directly add to aldehydes and imines affording a-hydroxy or a-amino ketones, respectively. The reaction of acylzirconocene chlorides with imines also proceeds under Bronsted acid-catalyzed conditions, even with aqneons acids. ... 

A variation that is more of an acyl addition (16-25) involves the reaction of an allylic alcohol with benzaldehyde. With a ruthenium catalyst and in an ionic liquid, the C=C unit reacts with the aldehyde, with concomitant oxidation of the allylic alcohol unit, to give a p-hydroxy ketone, PhCHO - -C=C—CH(OH)R PhCH(OH) CH(Me)COR. In another variation, formate esters add to alkenes using a ruthenium catalyst to give an alkyl ester via a formylation process. 

Aldehydes and ketones RCOR react with a-methoxyvinyllithium, CH2=C(Li)OMe, to give hydroxy enol ethers, RR C(OH)C(OMe)=CH2, which are easily hydrolyzed to acyloins, RR C(OH)COMe. ° In this reaction, the CH2=C(Li)OMe is a synthon for the unavailable H3C—C=0, °" and is termed an acyl anion equivalent. The reagent also reacts with esters RCOOR to give RC(OH)(COMe=CH2)2. A synthon for the Ph—C=0 ion is PhC(CN)OSiMe3, which adds to aldehydes and ketones RCOR to give, after hydrolysis, the a-hydroxy ketones, RR C(OH) C OH)COPh. ... 

E) Alcoholysis of Acyl Chlorides. Add 5 drops of acetyl chloride to 1 ml of ethanol. What is the product resulting from this reaction Can this test be used for detection of the hydroxyl group If so, try it with a less reactive hydroxy compound. 

Lithium aldimine (131), an acyl anion equivalent derived from an isocyanide and an organolithium reagent, adds to aldehydes giving, after quenching with water, a-amino ketones (134) via the Amadori rearrangement (Scheme 33)." The a-amino ketone (134) results from a double tautomerization of a-hydroxy imine (132), formed initially after quenching with water. Thus, the imine (132) isomerizes to enolamine (133), which in turn tautomerizes to the observed product (134). 

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