A Highly Efficient Procedure for Regeneration of Carbonyl Groups from their Corresponding Oxathioacetals and Dithioacetals Using Sodium Nitrite and Acetyl Chloride in Dichloromethane
Silica Gel-Supported Polyphosphoric Acid (PPA/SiO2) as an Efficient and Reusable Catalyst for Conversion of Carbonyl Compounds into Oxathioacetals and Dithioacetals
An Efficient Method for One-Pot Reductive Cleavage of Acetals to Primary Alcohols Using a Bimetal Redox Couple CoCl2.6H2O-Zn
作者:Kuladip Sarma、Amrit Goswami
DOI:10.2174/157017809789869456
日期:2009.10.1
Acyclic or cyclic O,O-acetals and O,S-acetals underwent reductivecleavage to give primary alcohols efficiently on treatment with Zn-CoCl2.6H2O-bimetal redox system in dry tetrahydrofuran at ambient temperature to give good to excellent yields.
LiBF<sub>4</sub> Catalyzed Chemoselective Conversion of Aldehydes to 1,3-Oxathiolanes and 1,3-Dithianes
作者:J. S. Yadav、B. V. S. Reddy、Sushil Kumar Pandey
DOI:10.1055/s-2001-10780
日期:——
Lithium tetrafluoroborate is found to be an efficient catalyst for the chemoselective protection of both aromatic and aliphatic aldehydes as 1,3-oxathiolanes and 1,3-dithianes under mild reaction conditions. Due to the neutral reaction conditions, this method is compatible with acid sensitive substrates.
An exceptionally simple and catalytic method for regeneration of carbonyl functionality from the corresponding 1,3-oxathiolanes
作者:Ejabul Mondal、Priti Rani Sahu、Gopal Bose、Abu T. Khan
DOI:10.1039/b110305a
日期:2002.4.9
A wide variety of 1,3-oxathiolanes 1 can be chemoselectively deprotected to the corresponding carbonyl compounds 2 in good yields by employing V2O5–H2O2 catalyzed oxidation of ammonium bromide in a CH2Cl2–H2O mixture at 0–5 °C. Some of the major advantages of this procedure are its mild conditions, and that it is highly selective and efficient, high yielding, and cost-effective. Furthermore, no brominations occur at the double bond or allylic position or α to the keto position or aromatic ring.
A Useful and Catalytic Method for Protection of Carbonyl Compounds into the Corresponding 1,3-Oxathiolanes and Deprotection to the Parent Carbonyl Compounds
作者:Ejabul Mondal、Priti Rani Sahu、Abu T. Khan
DOI:10.1055/s-2002-20466
日期:——
A wide variety of carbonyl compounds 1 can be easily protected to the corresponding 1,3-oxathiolanes 2 in good yields in the presence of catalytic amount of perchloric acid in dry CH2Cl2 at 0-5 °C. On the other hand, various 1,3-oxathiolanes 2 can be selectively deprotected to the parent carbonyl compounds 1 in very good yields by H2MoO4·H2O-H2O2 catalyzed oxidation of ammonium bromide in the presence of perchloric acid in CH2Cl2-H2O solvent system. Mild reaction condition, high selectivity, efficient and relatively good yields are some of the major advantages of the procedure.