Tong-Shuang Li

Montmorillonite Clay Catalysis XI1: Protection and Deprotection of Hydroxyl Group by Formation and Cleavage of Trimethylsilyl Ethers Catalysed by Montmorillonite K-10

Abstract An easy preparation of trimethylsilyl ethers of alcohols and phenols with 1,1,1,3,3,3-hexamethyldisilazane(HMDS) catalysed by montmorillonite K-10 at room temperature has been carried out in excellent yields. Desilyation of trimethylsilyl ethers is catalysed by K-10 in methanol at ambient temperature in high yields.

AN EFFICIENT AND FACILE PROCEDURE FOR THE DEPROTECTION OF 1,1-DIACETATES CATALYSED BY EXPANSIVE GRAPHITE

Abstract A rapid, efficient and high yield method for the deprotection of 1,1-diacetates is described which occurs under catalysis of expansive graphite in refluxing dichloromethane or benzene.

A Rapid Preparation of Acylals of Aldehydes Catalysed by Fe3+-Montmorillonite

Abstract Aldehydes can be converted to acylals by treatment with acetic anhydride in the presence of Fe3+-montmorillonite in excellent yield at room temperature.

An Efficient and Convenient Procedure for Preparation of 1,1-Diacetates from Aldehydes Catalysed by Expansive Graphite

Abstract An easy preparation of 1,1-diacetates from aldehydes has been carried out in excellent yield under catalysis of expansive graphite at room temperature.

Montmorillonite Clay Catalysis VI1: Synthesis of Triarylmethanes via Baeyer Condensation of Aromatic Aldehydes with N,N-Dimethylaniline Catalysed by Montmorillonite K-10

Abstract Triarylmethanes are synthesized in good to excellent yield via Baeyer condensation of aromatic aldehydes with N,N-dimethylaniline catalysed by montmorillonite K 10 at 100°C in the absence of solvent.

A FACILE PREPARATION OF METHOXYMETHYL ETHERS OF PRIMARY AND SECONDARY ALCOHOLS WITH DIMETHOXYMETHANE CATALYSED BY EXPANSIVE GRAPHITE

Abstract An easy preparation of methoxymethyl ethers of primary and secondary alcohols with dimethoxymethane has been carried out in excellent yield under catalysis of expansive graphite.

Montmorillonite Clay Catalysis I: An Efficient and Convenient Procedure for Preparation of 5(6)/5′(6′)-Unsaturated 3β-Disteryl Ethers

Abstract In the presence of montmorillonite K 10, 5(6)-unsaturated sterols (1) were heated at refluxing temperature in dichloromethane to provide 5(6)/5′(6′)-unsaturated 3β,3′β-disteryl ethers (4) in 69–73% yield. The mechanism of the reaction was discussed.

Montmorillonite Clay Catalysis. Part 31: A New Ready and High Yield Procedure for the Cleavage of Acetals Catalysed by Montmorillonite K 10

Abstract An easy cleavage of acetals has been carried out in excellent yield under catalysis of montmorillonite K 10 in refluxing wet acetone.

Studies on the Dehydrogenation of 9-Oxygenated-eudesma-4-en-3-ones with DDQ

Abstract 9-Acetoxy-eudesma-4, 11-dien-3-ones (4a, 4b) and 9-acetoxy-14-noreudesma-4, 11-dien-3-ones (5a, 5b) were treated with DDQ in dioxane to yield normal 1,2-dehydro-products, whereas 14-noreudesma-4, 11-dien-3, 9-diones (2a, 2b) afforded a rearranged aromatic product, 1-hydroxy-15-noreudesma-1, 3, 5 (10), 11-tetraen-9-one(3). No reaction was observed by treatment of eudesma-4, 11-dien-3, 9-diones (1a, 1b) with DDQ under the same conditions. The effect of 10-methyl configuration on this reaction is also discussed.