Others pivot from both bottom (like a hopper) and the side (like a casement). Also called Dual Action. Double-Hung Windows: Include offset upper and lower sashes, which can both move up and down in the frame. A window having two vertically sliding sash, each closing a different part of the window.
Reaction of sugar oxazolines with primary amines. In order to scrutinize the reaction pathway and structure of the reaction product, we started with a simple sugar oxazoline and a primary amine, carrying no other functional groups.
The idea which emerges from this is that a strong nucleophile can attack directly, without help from an acid catalyst. For a weak nucleophile, an acid catalyst is needed so that the carbonyl carbon is prepared to share a pair of electrons as a new covalent bond.If we look at the mechanism of reaction between an aldehyde and an amine, we see how these factors balance.he idea which emerges from this is that a strong nucleophile can attack directly, without help from an acid catalyst. For a weak nucleophile, an acid catalyst is needed so that the carbonyl carbon is prepared to share a pair of electrons as a new covalent bond.