A simple method for the synthesis of 1,3-dioxolanes from carbonyl compounds has been developed using 1,2-bis(trimethylsilyloxy)ethane in the presence of bismuth(III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap.
Regioselective transformation of alkynes into cyclic acetals and thioacetals with a gold(I) catalyst: comparison with Brønsted acid catalysts
作者:Laura L. Santos、Violeta R. Ruiz、Maria J. Sabater、Avelino Corma
DOI:10.1016/j.tet.2008.06.032
日期:2008.8
Au(I) catalyzes the transformation of alkynes into cyclic acetals and thioacetals at much higher rate than Brønsted acids. The reaction appears to be general for a range of alkynes and diols or dithiols, which are efficiently transformed with high selectivities. One of the salient features of this reaction process is the high reactivity of the enol ether or enol thioether intermediates, which undergo
Carbonyl compounds 1 were converted to the corresponding 1,3-dioxolanes 2 and 1,3-dioxanes 4 with ethylene glycol and 2,2-dimethyl-1,3-propandiol, respectively, in the presence of 1-3 mol% of N-(benzyl, 4-methylbenzyl or 4-methoxybenzyl)-2(or -4)-cyanopyridinium hexafluoroantimonates 3. The catalyst 3d was also effective for the tetrahydropyranylation.
The present invention relates to compounds of formula (A), as further defined herein, having antiviral activity, more specifically HIV (Human Immunodeficiency Virus) replication inhibiting properties. The invention also relates to pharmaceutical compositions comprising an effective amount of such compounds as active ingredients. The invention further relates to the use of such compounds, optionally combined with one or more other drugs having antiviral activity, for the treatment of animals suffering from viral infections, in particular HIV infection.
This invention relates to geranylgeranyl acetone (GGA) derivatives, pharmaceutical compositions comprising GGA derivatives and the use of GGA derivatives.