A Ring Expansion─Stereoselective Cycloaddition of Carbohydrate-Derived Donor–Acceptor Cyclopropanes: Synthesis of Bridged Oxepanone–Indole Hybrids
作者:M V Kamala Lakshmi、Intzar Ali、Ramu Sridhar Perali
DOI:10.1021/acs.joc.2c01652
日期:2022.9.16
investigated. The reaction condition is optimized by monitoring the progress at various temperatures, with various solvents, and with different Lewis acid catalysts. Under optimized conditions, high stereoselectivity and efficiency are achieved in most of the formed cycloadducts. The accessibility of the strategy is evaluated by utilizing an array of carbohydrate-derived donor–acceptorcyclopropanes and variably
An efficient one-pot synthesis of polyhydroxyalkyl-substituted pyrroles from 1,2-cyclopropa-3-pyranones with primary amines is reported. With 10% of InBr3 as the catalyst, both aryl- and alkylamines as well as various 1,2-cyclopropa-3-pyranones are well tolerated. This method is highly appealing because of its one-pot process, mild reaction conditions, substrate simplicity, and broad substrate scope.
A Ring Expansion–Glycosylation Strategy toward the Synthesis of Septano-oligosaccharides
作者:Perali Ramu Sridhar、Patteti Venukumar
DOI:10.1021/ol302677z
日期:2012.11.2
ring-expansion–glycosylation reaction was performed using 1,2-cyclopropanated sugars as glycosyl donors and carbohydrate O-nucleophiles as acceptors to provide septanohexose mimics of pyranose and furanosederivatives. The methodology was successfully extended to the synthesis of septano-oligosaccharides by adopting a divergent strategy as well as an iterative protocol.
Ringopening of 3-oxo-1,2-cyclopropanated sugars with thiols leads to the serendipitous discovery of the synthesis of sugar based homologated acyclic dithioacetals. These acyclic dithioacetals were found to undergo one-pot septanoside formation followed by stereoselective glycosylation in the presence of glycosyl acceptors under glycosylation reaction conditions.