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The most common protecting groups for carbonyls are acetals and typically cyclic acetals with diols. The runners-up used are also cyclic acetals with 1,2‑hydroxythiols or dithioglycols – the so-called O,S– or S,S-acetals. Ethylene glycol 1,3‑Propadiol
The formation of acetals reduces the total number of molecules present (carbonyl + 2 alcohol → acetal + water) and therefore is generally not favourable with regards to entropy. One situation where it is not entropically unfavourable is when a single diol molecule is used rather than two separate alcohol molecules (carbonyl + diol → acetal ...
Dioxolane is a heterocyclic acetal with the chemical formula (CH 2) 2 O 2 CH 2. It is related to tetrahydrofuran (THF) by replacement of the methylene group (CH 2) at the 2-position with an oxygen atom. The corresponding saturated 6-membered C 4 O 2 rings are called dioxanes.
The four phosphorus atoms are at the corners of a tetrahedron surrounding the palladium(0) center. This structure is typical for four-coordinate 18 e − complexes. [2] The corresponding complexes Ni(PPh 3) 4 and Pt(PPh 3) 4 are also well known.
TMSCl is reactive toward nucleophiles, resulting in the replacement of the chloride. In a characteristic reaction of TMSCl, the nucleophile is water, resulting in hydrolysis to give the hexamethyldisiloxane: + + The related reaction of trimethylsilyl chloride with alcohols can be exploited to produce anhydrous solutions of hydrochloric acid in alcohols, which find use in the mild synthesis of ...
Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone is used. Rotational effects and gravity are used to separate mixtures of solids and fluids. The ...
The term "acetyl" was coined by the German chemist Justus von Liebig in 1839 CE to describe what he incorrectly believed to be the radical of acetic acid (the main component of vinegar, aside from water), which is now known as the vinyl group (coined in 1851 CE); "acetyl" is derived from the Latin acētum, meaning "vinegar."
The arrangement of carbon atoms is the same in adamantane and diamond; [26] however, in the adamantane solid, molecules do not form a covalent lattice as in diamond, but interact through weak van der Waals forces. As a result, adamantane crystals are very soft and plastic. [17] [18] [27]