多取代α,β-不饱和酮的合成研究

α, β-Unsaturated ketonespossessmultiple reaction sites, including carbon-carbon unsaturated bonds, carbonyl and its α-position. Because they can undergo 1,4-conjugate addition, carbonyl related reactions, andAldol reaction, α, β-unsaturated ketones are thus potentialuseful building blocks in synthetic chemistrywith broad range of applications. The preparation of βmonoor dimethyl-substituted ketones is well established, however, the methods for that of multi-substitued α, β-unsaturated ketones remain scarce. Herein, we report two methods for the preparation of β-methyl and β-hydroxymethyl substitued enone 5 from cheap starting materials : 1) a sequence of alkyne acetylation, 1,4-conjugate addition of alkynone, andprotectinggroup removal; 2) selective allylic oxidation of dimethyl-substitued enone.