Mercury(II) Chloride-Cadmium Carbonate


[7487-94-7]  · Cl2Hg  · Mercury(II) Chloride-Cadmium Carbonate  · (MW 271.49) (CdCO3)

[513-78-0]  · CCdO3  · Mercury(II) Chloride-Cadmium Carbonate  · (MW 172.42)

(hydrolysis of thioacetals;1-5 glycosylation10)

Preparative Method: from the components in situ.

Handling, Storage, and Precautions: acute poison. Exposure to all mercury compounds is to be strictly avoided. Releases toxic Hg fumes when heated to decomposition. Protect from light.

The mixture of Mercury(II) Chloride and Cadmium Carbonate serves as a mild reagent for the hydrolysis of thioacetals1-3 and 1,3-dithianes (eqs 1-3).4-7 This method is particularly suited to the synthesis of chiral ketones from chiral aldehydes (using the umpolung methodology) because only a little racemization occurs at the a-carbon.4,5

Thioacetals derived from aldehydes often give lower yields than those made from ketones; in these cases the Mercury(II) Oxide/Boron Trifluoride Etherate mixture in THF/H2O is recommended.8

Thioglycosides react with alcohols such as cardenolides in the presence of HgCl2 and CdCO3 to give the corresponding glycosides.9 This reaction is generally nonstereoselective (e.g. both a- and b-glycosides are formed). However, neighboring group participation can ensure that only one anomer is produced in a kinetically controlled reaction (eq 4).10

1. (a) Larock, R. C. AG(E) 1978, 17, 27. (b) Larock, R. C. T 1982, 38, 1713. (c) Larock, R. C. Organomercury Compounds in Organic Synthesis; Springer: Berlin, 1985. (d) Larock, R. C. Solvomercuration/Demercuration Reactions in Organic Synthesis; Springer: Berlin, 1986.
2. (a) Fischer, E. CB 1894, 27, 673. (b) Wolfrom, M. L. JACS 1929, 51, 2138. (c) Arnold, H. W.; Evans, W. L. JACS 1936, 58, 1950.
3. English, J., Jr.; Griswold, P. H., Jr. JACS 1945, 67, 2039.
4. (a) Seebach, D. S 1969, 17. (b) Seebach, D.; Beck, A. K. OSC 1988, 6, 316.
5. (a) Corey, E. J.; Erickson, B. W. JOC 1971, 36, 3553. (b) Seebach, D.; Corey, E. J. JOC 1975, 40, 231.
6. (a) Seebach, D.; Kolb, M. CI(L) 1974, 687. (b) Seebach, D.; Beck, A. K. OS 1971, 51, 76.
7. Reece, C. A.; Rodin, J. O.; Brownlee, R. G.; Duncan, W. G.; Silverstein, R. M. T 1968, 24, 4249.
8. Jones, J. B.; Grayshan, R. CC 1970, 741.
9. CdCO3 on its own has also been used to facilitate glucosylation: Ko&cbreve;ovský, P.; Kosoev, K. K.; Procházka, &ZZbreve;. CCC 1973, 38, 3273.
10. (a) Wiesner, K.; Tsai, T. Y. R.; Jin, H. HCA 1985, 68, 300. (b) Wiesner, K.; Tsai, T. Y. R. PAC 1986, 58, 799.

Pavel Ko&cbreve;ovský

University of Leicester, UK

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