Diastereoselective Synthesis of Lincosamine Precursors

A Representative Synthetic Route for C5 Angucycline Glycosides: Studies Directed toward the Total Synthesis of Mayamycin

This study discloses an efficient synthetic route for the regiospecific construction of a C5 glycoside angucycline representative of mayamycin. The key steps are intramolecular aldol condensation and Hauser annulation, and the key precursor for the aldol reaction is accessible through utilization of α-lithiation of a vinyl ether.

Regioselective synthesis of naphthoquinone/naphthoquinol-carbohydrate hybrids by [4 + 2] anionic annulations and studies on their cytotoxicity

An efficient and regioselective synthetic route to naphthoquinone/naphthoquinol-carbohydrate hybrids has been developed. It is based upon anionic annulation of 3-nucleofugalphthalides with an acrylate appended sugar moiety. In each of the annulations studied, the arene-carbohydrate hybrids were obtained in good to excellent yields. The in vitro cytotoxic activity of the synthetic naphthoquinone/naphthonol-carbohydrate hybrids were evaluated against the human cervical cancer cell line (HeLa), and a few of them were found to exhibit potent anticancer activity against the cell line.

Grignard-mediated reduction of 2,2,2-trichloro-1-arylethanones

2,2,2-Trichloro-1-aryl-ethanones can be reduced by RMgX to the corresponding 2,2-dichloro-1-arylethen-1-olates and trapped with a range of electrophiles resulting in either reduction, reduction/aldol, reduction/Claisen condensation or reduction/aldol-Tishchenko products. In addition we demonstrate that 2,2-dichloro-1-arylethen-1-olates undergo counter-ion controlled Darzens condensations, which can be followed by a thermal rearrangement as a route to 1,3-diaryl-3-chloropropane-1,2-diones.