Alcohol unsaturated secondary

Selective oxidation of secondary alcohols to ketones is usually performed with CrOj/HjSO, I I in acetone (Jones reagent) or with CrOjPyj (Collin s reagent) in the presence of acid-sensitive groups (H.G. Bosche, 1975 C. Djerassi, 1956 W.S. Allen, 1954). As mentioned above, a,)S-unsaturated secondary alcohols are selectively oxidized by MnOj (D.G. Lee, 1969 D. Arndt, 1975) or by DDQ (D. Walker, 1967 H.H. Stechl, 1975). 

Aryl—OH ca 3610 (s) 1410-1310 (s) 1260-1180 (s) 1085-1030 (s) See comments under primary aliphatic alcohols Also for unsaturated secondary aliphatic alcohols... 

Sulfation andSulfamation. Sulfamic acid can be regarded as an ammonia—SO. complex and has been used thus commercially, always in anhydrous systems. Sulfation of mono-, ie, primary and secondary, alcohols polyhydric alcohols unsaturated alcohols phenols and phenolethylene oxide condensation products has been performed with sulfamic acid (see Sulfonation and sulfation). The best-known appHcation of sulfamic acid for sulfamation is the preparation of sodium cyclohexylsulfamate [139-05-9] which is a synthetic sweetener (see Sweeteners). 

Impurities consist of unreacted material, including alkanes and internal or branched alkenes, and other material which can be detected in the neutral oil fraction of AOS. Examination of this fraction also indicates the amount of unhydrolyzed material (sulfonate esters and sultones) and byproducts (secondary alcohols, unsaturated and 2-chloro-y-sultones) in the sample. Salt calculations are made to determine inorganic sulfates and sodium chloride. Determinations for alkalinity, color, and water are required to meet product... 

Cholesterol C27H45OH, an unsaturated secondary alcohol, contains the same ring system as the bile acids and is closely related to them genetically. Pseudocholestane, indeed, which is a stereoisomer of the parent hydrocarbon of cholesterol, cholestane, can be oxidised to cholanic acid by chromic acid with elimination of acetone (Windaus). 

Efficient kinetic resolution of chiral unsaturated secondary alcohols by irreversible enzyme-mediated acylation (with vinyl acetate as acylating agent, a crude preparation of Pseudomonas AK, and hexane as solvent) is possible, provided one relatively large and one small substituent are attached to the carbinol carbon. However, the method can be used to resolve substrates that are not amenable to asymmetric epoxidation (see examples 23, 25, 27, 29, where the double bond is either deactivated by an electron-withdrawing substituent, or is of the propargyl alcohol type). Acylation of the / -enantiomer consistently proceeds faster than that of the 5-enantiomer. An example of an allenic alcohol was also reported248. 

Interestingly, this strategy was applied to the more reactive propargyl alkoxides allowing for the simultaneously introduction of the three partners at the start of the reaction. In fact, in this case, no side reactions occurred [95]. This process is remarkably versatile, giving good yields of stereodefined 3-arylidene (and alkenyli-dene) tetrahydrofurans 105 with a variety of propargyl alcohols (primary, secondary, and tertiary) and unsaturated halides (aryl iodides, vinyl bromides, and tri-flates) (Scheme 8.45). 

Tin(IV) Chloride-catalyzed ene reaction of the pyruvate ester of (—)-8-phenylmenthol with 1-hexene gives a single diastereomer of the unsaturated (S)-a-hydroxy ester (de>90%) (eq 3). Similarly, tin(I V) chloride-catalyzed ene reactions of 8-phenylmenthyl glyoxylates afford unsaturated secondary alcohols with 93-98% de of the (S) configuration. ... 

Ceric ammonium nitrate or ceric sulfate is used to oxidize saturated and unsaturated secondary alcohols to ketones. The ceric salts are used only in catalytic amounts with sodium bromate as a reoxidant (equation 241) [741]. 

Of the new Pt catalysts reported since 1990 platinum complexes with new ligands and activators are noteworthy. Cyclodextrin complexes of platinum (as host-guest complexes) have been employed as hydrosilylation catalysts active at elevated temperature after releasing the guest compound [40]. Some other organic compounds have recently been used as activators (ligands) of Pt complexes, e. g., unsaturated secondary and tertiary alcohols and silylated unsaturated alcohols [41], alkadiynes, cyclooctadiene [42], and vinylnorbomene as well as quinones and methylnaphthoquinones [43]. 

Secondary alcohols having a C—OH stretching vibration that absorbs in the range cited for primary alcohols alpha, beta- unsaturated secondary alcohols C-OH stretching, 1074-1012 cnv1 alpha-chloro or bromo secondary alcohols C-OH stretching, near 1050 cnv1 Aromatic secondary alcohols... 

Potassium permanganate (KMn04) oxidises unsaturated secondary alcohols at the point of unsaturation. However, KMn04 supported on bentonite clay oxidises the hydroxyl group in preference to the alkene (e.g. equation 4.26) [122]. Unsaturated primary alcohols give virtually no reaction and allylic alcohols are oxidised much more readily than non-allylic ones. 

The catalytic oxidation of alcohols can be performed in the presence of organic halides. Saturated and unsaturated secondary alcohols can be converted to the corresponding ketones upon treatment with palladium(O) in the presence of aryl hahde and base (Scheme 15) U3H36]... 

The very interesting compounds 2a may be easily prepared from the corresponding unsaturated secondary alcohols by acid treatment, the anions 2b by deprotonation of the corresponding hydrocarbon as indicated by equ. 12a,b. 

Secondary alcohols can be oxidized in high yield to the corresponding ketones by bromobenzene in a reaction catalyzed by palladium acetate in the presence of a base and a phosphine ligand. These reaction conditions, when applied to A -, A -, and A -unsaturated secondary alcohols, yielded product mixtures. When the stoichiometric oxidant was bromomesitylene and a Pd(OAc)2 PPh3 ratio of 1 2 was used, the oxidation proceeded smoothly for a wide variety of alcohols (eqs 57 and 58). ... 

Compound (c) is unsaturated secondary alcohol. It will decolorize a Brj/CCI4 solution. Compound (d), on the other hand is an aldehyde. On treatment with chromic acid it will be oxidized to carboxylic acid. 

The enantioselective esterification of unsaturated secondary alcohols has been extensively studied [182] and has found several successful additional applications with substrates containing double bonds [183-188]. The results have been collected in Table 2 and Scheme 40, whereas Scheme 41 shows interesting examples of the resolution of hydroxy compounds that contain a triple bond in the molecule [189,190]. 

The alicyclic secondary alcohol, cycZohexanol, may be dehydrated by concentrated sulphuric acid or by 85 per cent, phosphoric acid to cyciohexene. It has a higher boiling point (82-83°) than amylene and therefore possesses some advantage over the latter in.the study of the reactions of unsaturated hydrocarbons. 

Clemmensen reduction of aldehydes and ketones. Upon reducing aldehydes or ketones with amalgamated zinc and concentrated hydrochloric acid, the main products are the hydrocarbons (>C=0 —> >CHj), but variable quantities of the secondary alcohols (in the case of ketones) and unsaturated substances are also formed. Examples are ... 

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