Physical Sciences and Mathematics Commons^™

A Concise Synthesis Of Β-Sitosterol And Other Phytosterols, Jiliang Hang, Patrick Dussault

Patrick Dussault Publications

A convenient synthesis of sidechain-modified phytosterols is achieved via a temporary masking of the stigmasterol 5,6-alkene as an epoxide. Following performance of the desired modification, the alkene is regenerated through a mild deoxygenation. The approach is applied to the syntheses of β-sitosterol and campesterol acetate, and suggests a facile route to the (Z)-isomers of Δ^22–23 phytosterols.

Includes Supplementary Data.

Efficient Synthesis And Conformational Investigations Of Cis-Pentacenediols, Jinyue Jiang, Charles E. Schiaffo, Chris P. Schwartz, Yong Pei, Joseph J. Dumais, Xiao Cheng Zeng, Patrick Dussault, Li Tan

Patrick Dussault Publications

Diisobutylaluminum hydride is utilized to reduce pentacene-6,13-diones to the corresponding diols, useful precursors to functionalized pentacenes. This pathway is mild and efficient, and produces the cis-diols as major products. Further, we found the cis-diols adopt endo conformation, which cannot flip to the exo conformation under ambient conditions. Due to the cis and endo orientation, the cis-diols can be potential bidentates in catalysis, molecular propellers, and optoelectronic devices.

Fragmentation Of Chloroperoxides: Hypochlorite-Mediated Dehydration Of Hydroperoxyacetals To Esters, Thomas J. Fisher, Patrick Dussault

Patrick Dussault Publications

Hypochlorites efficiently dehydrate hydroperoxyacetals to furnish the corresponding esters. The reaction, which can be accomplished with stoichometric Ca(OCl)₂ or with catalytic amounts of t-BuOCl, appears to involve formation and heterolytic fragmentation of secondary chloroperoxides, species not previously described in solution chemistry.

Includes Supporting Information (52 pp).

Plant Sterol And Stanol Substrate Specificity Of Pancreatic Cholesterol Esterase, Andrew W. Brown, Jiliang Hang, Patrick H. Dussault, Timothy P. Carr

Patrick Dussault Publications

Consumption of plant sterols or stanols (collectively referred to as phytosterols) and their esters results in decreased lowdensity lipoprotein cholesterol, which is associated with decreased atherosclerotic risk. The mechanisms by which phytosterols impart their effects, however, are incompletely characterized. The objective of the present study is to determine if pancreatic cholesterol esterase (PCE; EC 3.1.1.13), the enzyme primarily responsible for cholesterol ester hydrolysis in the digestive tract, is capable of hydrolyzing various phytosterol esters and to compare the rates of sterol ester hydrolysis in vitro. We found that PCE hydrolyzes palmitate, oleate and stearate esters of cholesterol, stigmasterol, stigmastanol and …