18.32It is the carbon atom flanked by two carbonyl groups that is involved in the enolization of terreicacid.Of these two structures, enol A, with its double bond conjugated to two carbonyl groups, is more sta-ble than enol B, in which the double bond is conjugated to only one carbonyl.18.33(a)Recall that aldehydes and ketones are in equilibrium with their hydratesin aqueous solution(Section 17.6). Thus, the principal substance present when (C6H5)2CHCH?O is dissolved inaqueous acid is (C6H5)2CHCH(OH)2(81%).(b)The problem states that the major species present in aqueous base is not(C6H5)2CHCH?O,its enol, or its hydrate. The most reasonable species is the enolate ion:18.34(a)At first glance this transformation seems to be an internal oxidation–reduction reaction. Analdehyde function is reduced to a primary alcohol, and a secondary alcohol is oxidized to a
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