Alcohols, cinnamyl-type

Birman has also shown that trans-cinnamyl type allylic sec-alcohols can be efficiently resolved using his CF3-PIP catalyst 25 (s = 6-26) or Cl-PIQ catalyst 26 (s = 17-57 see Scheme 8.5) [107]. Additionally, as noted earlier, Maruoka s NHC catalyst 29b was shown to resolve two trans-cinnamyl-type allylic sec-alcohols efficiently (s = 16 and 22 see Scheme 8.8). 

Higher oil content was reported in cinnamon leaf from Hyderabad (4.7%) compared with that from Bangalore (1.8%) (Mallavarapu et al., 1995). The two oils were of eugenol type and differed with respect to the relative amounts of linalool, cinnamal-dehyde, cinnamyl alcohol, cinnamyl acetate and benzyl benzoate. The essential oil of the leaves of C. zeylanicum from Cameroon contained eugenol (85.2%), (EJ-cinnamaldohyde (4.9%), linalool (2.8%) and /3-caryophyllene (1.8%) (Jirovetz et al., 1998). 

Reactions of propargyl trichlorosilane (21.90) with aromatic, heteroaromatic, and cinnamyl-type aldehydes (21.4), promoted by DMF, have been shown to occur in analogy to the allylation, producing allenyl alcohols 21.91 with >99 1 selectivity (Scheme 21.12). Similarly, allenyl trichlorosilane (21.92)... 

Another point for structural diversification is the sulfonamide group. Imai had already shown that a wide variety of groups could be introduced at this position to optimize the reaction. Since a wide variety of sulfonyl chlorides are commercially available, a number of different types of groups could be examined (Scheme 3.34). Testing of a variety of aryl and alkyl groups on the 1,2-cyclohexanediamine backbone demonstrates that the simple methanesulfonamide 122 is clearly superior or equal to many other analogs in the cyclopropanation of cinnamyl alcohol (Table 3.11). Another concern which was directly addressed by this survey was the question of catalyst solubility. 

Beside the Friedel-Crafts-type alkylation of arenes, the direct functionalization of 2,4-pentanediones is of great interest in Lewis acid catalysis. Although Pd-catalyzed Tsuji-Trost type allylations of 1,3-diketones are known, direct benzylation procedures catalyzed by Lewis acids are less explored [40-43]. Based on the previously described Friedel-Crafts alkylation of arenes and heteroarenes, the Rueping group developed a Bi(OTf)3-catalyzed benzylation of 2,4-pentanediones. Alcohols such as benzyl, allyl or cinnamyl alcohols were used as the electrophilic component to yield important 2-alkylated 1,3-dicarbonyl compounds. Initially, different Bi(III) salts were screened. In contrast... 

The second type of data is derived from biochemical experiments related to the three cinnamyl alcohols—/>-coumaryl alcohol (I), coniferyl alcohol (II), and sinapyl alcohol (III) and their phenolic glucosides— >-glucocoumaryl alcohol (IV), coniferin (V), and syringin (VI). These and the following formulas do not differentiate between cis and trans isomers. 

At present there is no single procedure available for the determination of ethylenic groups in lignin which can be applied reliably to any type of sample without regard for the particular structural environment in which these units exist. Hence, most of the more widely accepted methods essentially consist of procedures used for the determination of larger structural elements comprising lignin, for example, cinnamaldehyde, cinnamyl alcohol, and stilbene units, in which the carbon-carbon double bond is incorporated. 

The best reagents for reduction of olefinic aldehydes to olefinic alcohols are lithium aluminum hydride and sodium borohydride. Crotyl alcohol, CHjCH = CHCHjOH, and cinnamyl alcohol, CjH,CH =CHCHjOH, have been prepared in excellent yields. Cinnamyl alcohol is further reduced at higher temperatures to hydrocinnamyl alcohol. Citral, (CHj)jC =CHCHjCHjC(CH3)=CHCHO, may be selectively reduced to the ctOTesponding dienol by catalytic hydrogenation over platinum catalyst. A new method for the preparation of enediol esters of the type... 

The tinder fungus Fames fomentarius, which grows on both beech and birch trees, gives a deep red colour in alkali. This is associated with the presence of fomentariol (7.31), a purpurogallin type of oxidation product of trihydroxy-cinnamyl alcohol. 

Different types of end-groups are shown in Figure 7.7. End-groups of the cinnamyl alcohol (47) and cinnamaldehyde (48) types have been detected in both isolated lignins and lignins in wood. Quantitative analysis of MWL from spruce wood by H NMR spectroscopy suggests the presence of about 1% units of type 47 [40] and... 

Chloro-l-phenylpropene (cinnamyl chloride) was reductively dehalogenated in water/n-heptane biphasic systems by hydrogen transfer from formates using Pd(II) complexes with sulfonated phosphine ligands of the type 21 (Scheme 3.38) [271], Addition of polyether detergents increased the rate of hydrogenolysis and supressed the formation of alcohol... 

A similar type of oxidation was observed when alcohols reacted with DMSO. Traynelis and Hergenrother showed that benzylic and allylic alcohols were converted to the aldehyde in high yield by refluxing them in DMSO with air bubbling through the medium. 5 jjj j is case, air was a reagent and cinnamyl alcohol was oxidized in this manner to cinnamaldehyde in 90% yield. 5 Air is the oxidant and DMSO probably functions as a solvent. 

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