ChemInform Abstract: Cycloadditions of Allylsilanes. Part 11. Stereoselective Synthesis of Hydroxycyclopentanes and Hydroxymethylcyclobutanes by Titanium Tetrachloride-Promoted [3 + 2] and [2 + 2] Cycloadditions of Sterically Hindered Allylsilanes and Subsequent Oxidative Cleavage of the Carbon—Silicon Bond.

✍ Scribed by H.-J. KNOELKER; P. G. JONES; G. WANZL

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 36 KB
• Volume: 29
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199840034

✦ Synopsis

Cycloadditions of Allylsilanes. Part 11. Stereoselective Synthesis of Hydroxycyclopentanes and Hydroxymethylcyclobutanes by Titanium Tetrachloride-Promoted [3 + 2] and [2 + 2] Cycloadditions of Sterically Hindered Allylsilanes and Subsequent Oxidative Cleavage of the Carbon-Silicon Bond.

-Hydroxycyclopentanes (IV) and (VII) and hydroxymethylcyclobutene (X) are stereoselectively prepared by titaniumpromoted cycloaddition of allylsilane (II) with alkenes and subsequent oxidative cleavage of the primary cycloadducts. A modified Tamao-Fleming oxidation is used for the oxidative cleavage of the carbon-silicon bonds of the sterically very demanding silyl groups. The procedure involves a double protodesilylation of compounds (III), (VI), and (IX) to tert-butyldifluorosilyl derivatives as intermediates. -(KNOELKER, H.-