14507-49-4Relevant articles and documents
Preparation method of levonorgestrel intermediate ethyl lithium ammonia
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Paragraph 0028-0057, (2018/05/16)
The invention discloses a preparation method of levonorgestrel intermediate ethyl lithium ammonia. The preparation method includes the steps: (1) taking proton amine to react with alkali metal to prepare a reducing reagent; (2) taking organic solution of 18-methyl-3-methoxy-1, 3, 5 (10), 8-estratetraenol-17 beta-alcohol to react with the reducing reagent below 0 DEG C, and performing quenching, filtering, washing and draining to obtain a wet product; (3) adding the wet product into alcohol, performing refluxing, stirring, pulping and cooling, cooling the product at the temperature of -20 to 10DEG C for 4-24 hours, performing suction filtering, elution and draining, and drying the product at the temperature of 20-60 DEG C to reach constant weight to obtain the levonorgestrel intermediate ethyl lithium ammonia. The reducing reagent formed by proton amine is adopted to perform Birch reduction on 18-methyl-3-methoxy-1, 3, 5 (10), 8-estratetraenol-17 beta-alcohol, so that reaction temperature is increased, reaction difficulty is lowered, reaction yield and product purity are improved effectively, and environmental pollution caused in the reaction process is reduced.
Total synthesis with a chirogenic opening move demonstrated on steroids with estrane or 18a-homoestrane skeleton
Quinkert,Del Grosso,Doring,Doring,Schenkel,Bauch,Dambacher,Bats,Zimmermann,Durner
, p. 1345 - 1391 (2007/10/02)
A concept of first choice for the synthesis of the title compounds had been proposed by Dane in the late 1930s. It was soon turned down, because the opening move - a chirogenic Diels-Alder reaction - did not work. With Lewis acids as mediators, however, a successful start has been achieved now. With Ti complexes of chelating ligands (Seebach's TADDOLs (= α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols)), enantioselective formation of the desired adducts does occur. Efficient total syntheses of 2 and 3a have been accomplished.
Total-synthesis of (-)-norgestrel
Baier,Durner,Quinkert
, p. 1054 - 1068 (2007/10/02)
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