The aldol reaction is an important carbon-carbon bond formation reaction in organic chemistry. In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form an aldol (â-hydroxy ketone), a structural unit found in many naturally occurring molecules and pharmaceuticals. Sometimes, the aldol addition product loses a molecule of water during the reaction to form an á,â-unsaturated ketone. This is called an aldol condensation. The aldol reaction was discovered independently by Charles-Adolphe Wurtz and by Alexander Porfyrevich Borodin in 1872. Borodin observed the aldol dimerization of 3-hydroxybutanal from acetaldehyde under acidic conditions. The aldol reaction is used widely in the large scale production of commodity chemicals such as pentaerythritol. The aldol structural motif is especially common in polyketides, a class of natural products from which many pharmaceuticals are derived, including the potent immunosuppressant FK506, the tetracycline antibiotics, and the antifungal agent amphotericin B. Extensive research on the aldol reaction has produced highly efficient methods which enable the otherwise challenging synthesis of many polyketides in the laboratory.
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Today's selected anniversaries:
The United States Navy battleship USS Maine exploded and sank in Havana, Cuba, killing more than 260 people and precipitating the Spanish-American War.
World War II: Japanese forces led by General Tomoyuki Yamashita captured Singapore, the largest surrender of British-led military personnel in British history.
The British pound sterling and the Irish pound were decimalised on what is called Decimal Day.
The Soviet Union officially announced that all of its troops had withdrawn from Afghanistan after a nine-year conflict.
In one of the largest anti-war rallies in history, millions around the world in approximately 800 cities took part in protests against the impending invasion of Iraq.
Wiktionary's word of the day:
To shed or cast off a covering, especially a skin; to slough; to moult
Wikiquote quote of the day:
Kings had always been involving and impoverishing their people in wars, pretending generally, if not always, that the good of the people was the object. This our convention understood to be the most oppressive of all kingly oppressions, and they resolved to so frame the Constitution that no one man should hold the power of bringing this oppression upon us. --Abraham Lincoln