Primary alcohols copper bromide

The diazoketoester 20 undergoes cyclopropanation to the unstable pentacycle 6 (major product) when added dropwise to a solution of copper(ll)bis-salicylalde-hyde-/-butylimine in toluene, involving the intermediate carbene 7. Sodium boro-hydride reduces 6 in methanol solution to the secondary alcohol which is, for protection, converted to the benzyleflier 21 by Williamson synthesis involving deprotonation to the alcoholate by sodium hydride and 0-alkylation by benzyl-bromide so that diisobutylaluminumhydride (DIBAH) reduces the i-butylester in 21 to the primary alcohol 22 in dichloromethane. 

Subsequently, compound 91 was elaborated to primary alcohol 92 with the H-ring functionality in a similar manner to the Sasaki synthesis (Scheme 11). For the introduction of the triene side chain, a simple and practical method for the stereoselective synthesis of (Z)-vinyl iodide, which is expected to be more reactive than the bromide counterpart, was developed [105]. Thus, PCC oxidation of alcohol 92 followed by treatment of the resultant aldehyde with tetraiodomethane and triphenylphosphine gave diiodoalkene 93. Reduction of 93 with the zinc-copper couple in the presence of acetic acid provided (Z)-vinyl iodide 94 in high yield. Since deprotection of the fully protected... 

General Synthesis and Reactions.—Linear primary alcohols with at least seven carbon atoms are transformed into esters in high yield using copper oxide at temperatures above 170 C in the liquid phase. RusfCO) catalyses the conversion of an aldehyde, or an alcohol with the same number of carbon atoms, into an ester in the presence of diphenylacetylene. " The carbonylation of organic halides in the presence of cyclic ethers is catalysed by PhPdI(PPh3)2 , it provides a synthesis of halohydrin esters in reasonable yield. Cyanohydrin esters have been synthesized by the sodium borohydride reduction of acyl cyanides in the presence of tetra-n-butylammonium bromide. ... 

Oxidation of Alcohols. Alkoxymagnesium bromides of secondary alcohols and allylic and benzyhc alcohols are oxidized to the corresponding ketones or aldehydes with N-chlorosuccinimide in the presence of r-BuOLi. The method is ineffective for primary saturated and some unsaturated alcohols, but oxidations of the former substrates to aldehydes occur readily if t-butoxymagnesium bromide is substituted for f-BuOLi. Secondary alcohols (eq 2) and primary benzylic (eq 3) and allylic alcohols are oxidized to the corresponding carbonyl compounds in good yields using 2—3 equiv of a 1 1 mixture of copper(II) bromide—r-BuOLi in THF at rt. However, the reagent is not effective for the conversion of primary aliphatic alcohols to aldehydes. 

After the first works on the copper-catalyzed aiylation of alkyl amines in the presence of ethylene glycol (2 equiv.) L15 [134] or diethylsalicylamide (5-20 mol%) L16 [135] as ligands, Buchwald reported in 2006 a room-temperature procedure for this type of reaction (Scheme 4). The condensation of primary or secondary alkyl amines [136, 137], and amino alcohols (selective N- versus O-arylation) with aryl iodides was performed at 25°C, thanks to the help of cheap 1,3-diket(Mie ligands L17 associated with Cul (5%). Harsher cmiditions (90°C) had to be applied from aryl bromides (Scheme 4). 

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