Hydroxy alkylation

Coumarin, 6-ethoxycarbonyl-4,5,7-trihydroxy-synthesis, 3, 805-806 Coumarin, 3-hydroxy-Mannich reaction, 3, 680 mass spectra, 3, 609 Coumarin, 4-hydroxy-alkylation, 3, 692 azo dyes from, I, 331 electrophilic substitution, 2, 30 IR spectra, 3, 596 Mannich reaction, 3, 680 mass spectra, 2, 23 3, 609 molecular structure, 3, 622 reactions... 

Diels-Alder cycloaddition reactions, 2, 350 tautomerism, 2, 27, 152, 347 Isoquinoline, 4-hydroxy-alkylation, 2, 349 sulfonation, 2, 321... 

Pyrazino[2,3-d]pyridazin-8-one, 5-chloro-synthesis, 3, 347 Pyrazino[l, 2-a]pyrimidine reactions, 3, 350 structure, 3, 339-340 synthesis, 3, 256, 365 Pyrazino[ 1,2-a]pyrimidine, 2-hydroxy-alkylation, 3, 351... 

On the other hand, the fluorine-induced addition of the diastereomeric silyl-subsliluted sulfides 36 A and 36B to benzaldehyde proceeds without loss of stereochemical information and with retention of configuration32. Since, however, the anionic reagent 35A/35B is known to be configurationally labile, the observed retention of configuration in the fluorine-induced desi-lylative hydroxy alkylation lends experimental evidence to the notion that these reactions proceed via hypervalent silicon species rather than anionic reagents. 

Oxirane ergeben mit Natrium-trithio-dihydrido-borat Bis-[2-hydroxy-alkyl]-di-sulfane, die mit Lithiumalanat zu 2-Hydroxy-thiolen gespalten werden z.B.4 ... 

So wird z. B. in 4-(l-Hydroxy-alkyl)-pyridinen die Hydroxy-Gruppe mit sehr guten Ausbeuten hydrogenolytisch unter Racemisierung entfernt2 ... 

The condensation of aromatic rings with aldehydes or ketones is called hydroxy-alkylation. The reaction can be used to prepare alcohols, though more often the alcohol initially produced reacts with another molecule of aromatic compound (11-12) to give diarylation. For this the reaction is quite useful, an example being the preparation of l,l,l-trichloro-2, 2-bis (p-Chlorophenyl) ethane (DDT) ... 

R = H, halo, hydroxy, alkyl, alkoxy X = H, sulpho, carboxyl, sulphonamide Y = alkylene, cycloalkylene linkages... 

Treves, K., Shragina, L., Rudich, Y. (2001) Measurement of octanol-air partition coefficients using solid-phase microextraction (SPME) - application to hydroxy alkyl nitrates. Atmos. Environ. 35, 5843-5854. 

The ring rearrangement of 8a-(l-hydroxy-alkyl)-hexahydro-oxazolo[3,4- ]pyridin-3-ones 163 upon treatment with sulfuryl chloride was reported in 2004 activation of the alcohol and ring extension produces 5,6-dihydro-l//-oxazolo[3,4-tf]azepin-3-ones 164 in excellent yields (Scheme 48) <2004H(63)17>. 

Substituents with lone electron pairs, such as alkoxy, hydroxy, alkyl, and aryl-amino groups, are known as electron donors. The CH3 group, despite the absence of such free electron pairs, is also considered an electron donor. Functional groups with conjugated rr-electron systems, such as NOz, COOH, COOR, SOz, or SOzAr act as electron acceptors. 

Recently, Trost et al. reported the vanadium-catalyzed addition reaction of 2,3-allenols [180], Here the oxygen in 401 served as an intramolecular nucleophile to attack the center carbon atom of allene to form a vanadium enolate 402. Aldol condensation of 402 with an aldehyde afforded (2-hydroxy)alkyl vinylic ketones 403. 

Lactones and lactams have also be prepared by the carbonylation of 2-(co-hydroxy-alkyl)- and 2-(co-aminoalkyl)bromobenzenes [29] (see Section 8.3). 

The two-step activation of oxazolidinones is depicted in Fig. 8.26. Hydrolysis yields an A-(l -hydroxy alkyl) derivative, which breaks down to liberate the peptide or A-acylamino acid (Fig. 8.26, Reactions a and b). Since oxazolidinones are prepared by the condensation of a peptide and an aldehyde (Fig. 8.26, Reaction c), the reverse reaction (i. e., one-step activation) cannot be excluded. Examples of this type of prodrug are provided by a series of oxazolidinones of the general structure 8.190 (R = PhCH20 R = H, Me, i-Pr, or PhCH2 R" = H, Me, or Ph Fig. 8.26) [248]. In phosphate buf-... 

H. Bundgaard, G. J. Rasmussen, Prodrugs of Peptides. 9. Bioreversible JV-a-Hydroxy-alkylation of the Peptide Bond to Effect Protection against Carboxypeptidase or other Proteolytic Enzymes , Pharm. Res. 1991, 8, 313-322. 

These adducts, submitted to MCPBA oxidation, undergo telluroxide elimination, regenerating the original C=C bond. The overall transformation therefore provides a-hydroxy-alkylation of a,jS-unsaturated carbonyl compounds. ... 

Photochemical a-hydroxyalkylation by alcohols is strictly connected with photochemical alkylation. With quinoline an acidic medium leads to alkylation hydroxy alkylation takes place with nonprotonated bases. The suggested mechanism is substantially identical for both processes. A IT -> 7T excited state would cause the initial hydrogen abstraction (Scheme 11). 

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