Cyclic primary alcohol

When simple terminal alkenes are used as acceptors, the cyclic primary alkyl cobalt species are stable, and can often be isolated and purified by standard techniques.145 Scheme 32 shows some of the transformations that Pattenden has accomplished with the cyclic alkylcobalt complex (55).146 In addition to standard elimination to an alkene, the complexes can be converted to alcohols, halides, oximes, and phe-... 

As mentioned before a PEG-supported TEMPO proved to be very efficient in the oxidation of 1-octanol to octanal not only with sodium hypochlorite, but also in combination with different terminal oxidants such as bis(acetoxy)iodobenzene and trichloroisocyanuric acid. This reaction could be extended to acyclic and cyclic primary and secondary alcohols with excellent results. It is remarkable that the PEG-supported TEMPO maintained the good selectivity for primary vs secondary ben-zylic alcohol oxidation typical of non-supported TEMPO. 

The ease of acetal formation depends largely on the structures of the reacting carbonyl compounds and alcohol.905 Primary alcohols react better than secondary or tertiary ones the ease of reaction of carbonyl compounds decreases in the order formaldehyde, aliphatic aldehydes,, / -unsaturated aldehydes, aromatic aldehydes, ketones acetone gives cyclic ketals very readily with 1,2- and 1,3-diols. 

When primary amines were used in this reaction instead of alcohols, cyclic carbamates 12 were formed (Scheme 7) [21]. Yields of 4-methyleneoxazolidin-2-ones 12 were foxmd to depend on the amine structiu e, while steric factors and nucleophilicity of amines were found to govern the reaction outcome. No product was formed in attempts to involve f-butylamine in the reaction. Yields of 4-methylene-3-phenyloxazolidin-2-ones (12, R3=Ph) obtained from aniline were also low (15-38%). Contrarily to the reaction of 10 with CO2 in the absence of external nucleophiles, under tire same condition in the presence of n-butylamine, an E-isomer of the corresponding cyclic carbamate was isolated in equal quantity with the Z-isomer (51% overall yield). 

Conversion to dialkyl ethers (Sec tion 15 7) On being heated in the presence of an acid catalyst two molecules of a primary alcohol combine to form an ether and wa ter Diols can undergo an intramo lecular condensation if a five membered or six membered cyclic ether results... 

Secondary aliphatic alcohols 3625-3620 (s) 1350-1260 (s) 1125-1085 (s) See comments under primary aliphatic alcohols Also for a-unsaturated and cyclic tertiary aliphatic alcohols... 

CH2=C(OBn)CH2F, PdCl2(COD), CH3CN, it, 24 h, 89-100% yield. Protic acids can also be used to introduce this group, but the yields are sometimes lower. A primary alcohol can be protected in the presence of a secondary alcohol. This reagent also does not give cyclic acetals of 1,3-diols with palladium catalysis. 

In cases where two 1,2-acetonides are possible, the thermodynamically more favored one prevails. Secondary alcohols have a greater tendency to form cyclic acetals than do primary alcohols, but an acetonide from a primary alcohol is... 

X0 to hydroxy compounds. Lower temperatures favor ketone formation and sterically hindered carbonyls, such as 2-thienyl t-butyl ketone, are not reduced. The sensitivity of desulfurization to steric factors is evident by the failure to desulfurize 2,5-di-i-butyl-3-acetylthiophene. The carbonyl groups of both aldehydes and ketones can be protected by acetal formation, as particularly cyclic acetals are stable during desulfurization in methanol at room temperature. " The free aldehydes give primary alcohols on desulfurization. Another method to obtain only keto compounds is to oxidize the mixtures of ketone and secondary alcohol with CrOs after the desulfurization. - Through the desulfurization of 5,5 -diacetyl-2,2, 5, 2"-terthienyl (228), 2,15-hexadecandione (229) has been obtained, which... 

The thermolysis of xanthates derived from primary alcohols yields one olefin only. With xanthates from secondary alcohols (acyclic or alicyclic) regioisomeric products as well as fi/Z-isomers may be obtained see below. While acyclic substrates may give rise to a mixture of olefins, the formation of products from alicyclic substrates often is determined by the stereochemical requirements the /3-hydrogen and the xanthate moiety must be syn to each other in order to eliminate via a cyclic transition state. 

Myrtenol, CjpHjgO, is a primary cyclic alcohol, which was isolated from essential oil of myrtle, in which it occurs principally in the form of its acetic ester, by von Soden and Elze. It is separated from geraniol, with which it is found, by fractional distillation, and by the crystallisa-... 

Grignard reagents react with oxetane, a four-membered cyclic ether, to yield primary alcohols, but the reaction is much slower than the corresponding reaction with ethylene oxide. Suggest a reason for the difference in reactivity between oxetane and ethylene oxide. 

The addition, therefore, follows Markovnikov s rule. Primary alcohols give better results than secondary, and tertiary alcohols are very inactive. This is a convenient method for the preparation of tertiary ethers by the use of a suitable alkene such as Me2C=CH2. Alcohols add intramolecularly to alkenes to generate cyclic ethers, often bearing a hydroxyl unit as well. This addition can be promoted by a palladium catalyst, with migration of the double bond in the final product. Rhenium compounds also facilitate this cyclization reaction to form functionalized tetrahydrofurans. 

The reactivity of hydrido(ethoxo) complex 4 was examined (Scheme 6-15) [8]. Metatheses similar to those postulated for alcohol exchange (Eq. 6.5) occurred between HCl, LiCl, phenyl acetate or primary amines and yielded complexes 94. The reaction of 4 with cyclic anhydrides proceeded similarly to give iridium-assisted ring opening products 95. Heterocumulenes afforded the inserhon products 96 into the Ir-O bond. 

---