P-methoxyphenyl acetal

Conversion of a 1,2- or 1,3-diol to the p-methoxyphenyl acetal (see below) followed by regioselective reductive cleavage of the acetal using diisobutylalane can be used for the differential protection of a 1,2- or 1,3-dioL. In the example shown in Scheme 4.198, two regioisomeric cleavage products were obtained (8 1) with the major p-methoxybenzyl ether being isolated in 72% yield.144 A related transformation has been applied to 3,4-dimethoxyphenyl acetals.365... 

If light-induced electron transfer is the crucial step in a photochemical reaction, the solvent dependence expected for this process (cf. Section 5.5.3) may carry over to the whole reaction. An example is the reaction of l-cyano-naphthalene (14) with donor-substituted acetic acids such as p-methoxyphenyl-acetic acid (15). 

However, both amino groups of A,A-acetals may be replaced in other cases morpholinium dimorpholinoacetate and anisole give di-(p-methoxyphenyl)-acetic acid in 74% yield 821... 

See Homoanisaldehyde and under Hydroxy-phenylacetaldehyde. p-Methoxyphenyl acetate. 

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