Oxo and Hydroxy Side-chain Substituted Compounds

Apart from the hydroxy pentadecyl compounds reported in the orsellinic series (ref. 14), the long chain compounds constituting the gingerols, for example, 4-hydroxy-3-methoxy-(5 -hydroxy-3 -oxoalkyl)ben2enes have attracted synthetic interest. Thus three members of the (+)-(S)-gingerol series, the C q side chain compound, designated (+)(S)[6], and the homologous C 2 14 compounds have been 

The details of reagents for the synthesis of the epoxide are given in (a) and the second stage for (+)(S)[10]-gingerol in (b). With (+)(S)[8]-gingerol, at vi, EtjCuCNLij was employed and with ( )(S)[6]-gingerol, the tosylate was reduced with LAH. 

The synthesis of 5-(2-oxoalky0resorcinols which are present in Cereale secale has been simply effected by the reaction of 3,5-dimethoxyphenylacetyl chloride with a dialkyl cadmium reagent in the folowing way (ref. 99). The 2-hydroxy compound shown as the final product is also present in the phenolic lipids of rye. 

Reagents (i) KOH, EtOH H3O (ii) SOCI2 (iii) (Ci5H3i)2Cd, Et20 H3O (iv) BBra, CH2CI2 (v) NaBH4, MeOH. 

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