Addition reactions 3-hydroxy alkyl mercury

Hydroxy alkyl) mercury(II) acetates and NaBH4 react to form carbon-centered radicals through the reaction steps shown in Figure 1.14. When methyl acrylate is present in the reaction mixture, these radicals can add to the C=C double bond of the ester (Figure 1.15). The addition takes place via a reaction chain, which comprises three propagation steps. 

Reaction of the anion prepared by deprotonation of a ketene thioacetal (799) (LDA or s-butyllithium) with a carbonyl compound has been shown to afford generally the product of y-addition (800) (80JOC2236). Mercury ion-assisted hydrolysis of the 5-hydroxy ketene thioacetal provides access to a y-lactone (801 Scheme 187). The y-selectivity of carbonyl substrates is to be contrasted with the a-selectivity generally exhibited by alkyl halides in... 

The intramolecular additions of alkoxyl groups to carbon-carbon double bonds to give P-iodo-alkyl ethers from alkyl hypoiodites under photolytic conditions have been reported. Suginome and collaborators found that the formation of a-iodoepoxides arising from an intramolecular a, P-addition of an allylic alkoxyl radical is a major general process in the photolysis of tertiary and some secondary allylic alcohol hypoiodites in the presence of mercury (11) oxide and iodine in benzene. Thus, 5-hydroxy-SP-cholest-3-ene gave epimeric a-iodoepoxides in a ratio of 10 1 in 86% yield as outlined in Scheme 86. Similar reaction of l-alkylcyclohex-2-en-l-ols gave a mixture of cis- and tr s-a-iodoepoxides (Scheme 87). The addition of pyridine dramatically enhanced the yield of the addition product. The yields of the a-iodoepoxides obtained from the photolysis of l-alkylcyclohex-2-en-l-ols and the ratios of cis- to trans-isomers are summarized in Table 109.1. 

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