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Cholesterol total synthesis

Cholesterol total synthesis in chemistry describes the total synthesis of the complex biomolecule cholesterol and is considered a great scientific achievement.[1] The research group of Robert Robinson with John Cornforth (Oxford University) published their synthesis in 1951 [2] and that of Robert Burns Woodward with Franz Sondheimer (Harvard University) in 1952.[3] Both groups competed for the first publication since 1950 with Robinson having started in 1932 and Woodward in 1949. According to historian Greg Mulheirn the Robinson effort was hampered by his micromanagement style of leadership and the Woodward effort was greatly facilitated by his good relationships with chemical industry. Around 1949 steroids like cortisone were produced from natural resources but expensive. Chemical companies Merck & Co. and Monsanto saw commercial opportunities for steroid synthesis and not only funded Woodward but also provided him with large quantities of certain chemical intermediates from pilot plants. Hard work also helped the Woodward effort: one of the intermediate compounds was named Christmasterone as it was synthesized on Christmas Day 1950 by Sondheimer.

Other cholesterol schemes have also been developed: racemic cholesterol was synthesized in 1966 by W.S. Johnson,[4] the enantiomer of natural cholesterol was reported in 1996 by Rychnovsky and Mickus,[5] in 2002 by Jiang & Covey [6] and again in 2008 by Rychnovsky and Belani.[7]

The molecule[edit]

Cholesterol is a tetracyclic alcohol and a type of sterol. Added to the sterol frame with the alcohol group at position 3 are 2 methyl groups at carbon positions 10 and 13 and a 2-isooctyl group at position 17. The molecule is unsaturated at position 5,6 with an alkene group. The total number of stereocenters is 8. The unnatural cholesterol molecule that has also been synthesized is called ent-cholesterol. Cholesterol overview

Woodward Cholesterol Synthesis @ SynArchive.com