ZrCl<sub>4</sub> as an Efficient Catalyst for a Novel One-Pot Protection/Deprotection Synthetic Methodology
作者:Surendra Singh、Colm D. Duffy、Syed Tasadaque A. Shah、Patrick J. Guiry
DOI:10.1021/jo800932t
日期:2008.8.1
found to be an efficientcatalyst for the one-pot esterification and deprotection of (5S,6R)-5,6-diacetoxyoct-7-enoic acid in good yields (44−62%) with a lactone formed as a minor byproduct. ZrCl4 (10−20 mol %) was also sufficient to deprotect 1,3-dioxalane, bis-TBDMS ethers, and diacetate functional groups in excellent yields of up to 93%. ZrCl4 (1−10 mol %) also promoted diol protection as the acetonide
Microwave-Assisted Synthesis of Substituted Tetrahydropyrans Catalyzed by ZrCl<sub>4</sub> and Its Application in the Asymmetric Synthesis of <i>exo</i>- and <i>endo</i>-brevicomin
作者:Surendra Singh、Patrick J. Guiry
DOI:10.1021/jo901019u
日期:2009.8.7
ZrCl4-catalyzed deprotection of 1,3-dioxane/dioxalane and the simultaneous formation of 6-methoxy-substituted tetrahydropyrans proceeded under microwave irradiation in good yield. This synthetic methodology was used for the asymmetric synthesis of (+)-exo- and (+)-endo-brevicomin in 55% overall yield over 4 steps.