Homo-allylic alcohols preparation

Similarly, 5-lactols and 5-lactones are obtainable from the corresponding homo allylic alcohols. With dehydration, the corresponding dihydropyrans are prepared. Spirocyclic y-butyrolactones of this type and the corresponding 5-lactones are widespread in nature and play a key role as synthetic intermediates. 

Y. Nakamura, M. Okada, H. Horikawa, T. Taguchi, Preparation of c5-fluorinated homo-allylic alcohol derivatives via regioselective hydride reduction of allylic alcohol derivatives, J. Fluor. Chem. 117 (2002) 143-148. 

The Ni-catalyzed coupling is a superior method for the preparation of unsymmetrical 1,5-dienes, an allylic nucleophile being generated from fragmentation of a tertiary homo-allylic alcohol. ... 

The preparation of an organoaluminium reagent which, although of undetermined composition, is considered to possess a tin-aluminium bond, and its use in converting allylic phosphonates into homo-allylic alcohols in the presence of a palladium catalyst have been described (Scheme 23). ... 

General Considerations. A sequence involving metalation, alkylation, and fluoride-induced elimination of benzenesulfinate allows the conversion of (2) to a terminal alkene. An analogous sequence involving a double alkylation of (2) provides a 1,1-disubstituted alkene (eq 2). The Uthio derivative of (2) has also been used to prepare cyclopropyUdene derivatives, homo-allylic alcohols, and aUyl silanes via the Julia alkenation. ... 

Mukaiyama, T. Harada, T. Shoda, S. (1980) An efficient method for the preparation of homo allylic alcohol derivatives by the reaction of allyl iodide with carbonyl compounds in the presence of stannous halide, Chem. Lett., 1507-10. 

The preparation of the requisite y-keto-p-toluenesulfonate rac-35 as homo-Favorskii precursor commenced with commercially available 2,5-dihy-droanisole (36) that was protected and epoxidized to acetal rac-31 (Scheme 11). Regioselective opening of the epoxide with p-chlorophenylse-lenide followed by sequential oxidation to the selenoxide and thermal elimination generated an allylic alcohol that was protected to give pivaloate rac-38. 

Ferulic acid, a phenolic acid that can be found in rapeseed cake, has been used in the synthesis of monomers for ADMET homo- and copolymerization with fatty acid-based a,co-dienes [139]. Homopolymerizations were performed in the presence of several ruthenium-based olefin metathesis catalysts (1 mol% and 80°C), although only C5, the Zhan catalyst, and catalyst M5i of the company Umicore were able to produce oligomers with Tgs around 7°C. The comonomers were prepared by epoxidation of methyl oleate and erucate followed by simultaneous ring opening and transesterification with allyl alcohol. Best results for the copolymerizations were obtained with the erucic acid-derived monomer, reaching a crystalline polymer (Tm — 24.9°C) with molecular weight over 13 kDa. 

A general method for the preparation of 3,7-substituted allyl alcohols with (Z)-configuration has been developed with alkyllithium. The regioselectivity of the reactions of alkynyllithium and oxiranes ° ° and the effects of the solvent and (Me2N)3PO ° have been investigated with regard to the formation of homo-propargyllic alcohols. The stereochemistry of the process has been studied in the reactions of as- and fra 5-neopentylallyllithium with cyclohexene oxide and fra s-2,3-butene oxide. 

In order to efTectively obtain products of homo-Claisen rearrangement [24], Wilson et al. prepared the propionate esters of the allylic alcohol 3 and treated them with LDA. The enolate so generated, on warming to room temperature, gave the S, a-unsaturated acid in good yield after heating the rearrangement product with methanolic hydrochloric acid (Scheme 5.1.13). 

The structure of ( —) 2P-acetoxy-1 la-hydroxyverrucosane (544) was established as follows (Scheme 65). Jones oxidation of (544) gave a five-membered ketone (551). Acid treatment of the latter resulted in homoallylic ring expansion to homo-allylic ketoalcohol (552) which was converted via the tosylhydrazone into (548) identical with the homoallylic alcohol prepared from (547) via (545) (Scheme 64). That the 11-hydroxyl group was a was inferred from the remarkable downfield shifts exhibited by the C-10 and the C-12 methyl groups of the five-membered ketone (551) and the small solvent shift exhibited by the C-10 methyl group (553) and its homoallylic ring expanded product. 

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