- Preparation method of levonorgestrel intermediate ethyl lithium ammonia
-
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.
- -
-
Paragraph 0028-0057
(2018/05/16)
-
- SILICA GEL PROMOTED SELECTIVE HYDROLYSIS OF 3-METHOXY-2,5(10)-DIENE STEROIDS
-
Hydrolysis of 3-methoxy-2,5(10)-diene steroids (1a-c) via oxalic acid in the presence of silica gel was developed as a fast selective synthesis method toward corresponding 5(10)-en-3-ones (2a-c) in good yield (51-94percent).This also provided a new method for selective ketalisation of 17-keto over 3-keto (2c).
- Lui, Li-Gong,Zhang, Tong,Li, Zhen-Su
-
p. 2999 - 3006
(2007/10/03)
-
- Total synthesis with a chirogenic opening move demonstrated on steroids with estrane or 18a-homoestrane skeleton
-
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.
- Quinkert,Del Grosso,Doring,Doring,Schenkel,Bauch,Dambacher,Bats,Zimmermann,Durner
-
p. 1345 - 1391
(2007/10/02)
-
- Direct Conversion of 13β-Alkylgonatetraenes into 13β-Alkylgon-4-en-3-ones
-
Birch reduction of 8,9-didehydroestradiol-17β 3-methyl ether 1 or 9(11)-didehydroestradiol-17β 3 methyl ether 2 followed by acid hydrolysis results in a mixture of 19-nortestosterone 8 and 19-nor-9β,10α-testosterone 9 in varying amounts.However, reduction of their acetates with sodium or lithium, tert-butyl alcohol in liquid ammonia and in the presence of aniline affords exclusively 19-nortestosterone.Similarly, 18α-homo-19-nortestosterone 12 is prepared from the acetate of 18α-homoestradiol-17β 3 methyl ether, 10.
- Bijoy, Panicker,Ramachandran, Uma,Rao, G. S. R. Subba
-
p. 2331 - 2334
(2007/10/02)
-
- Synthesis of gon-4-enes
-
1. A therapeutic composition having progestational activity comprising as active ingredient a 17-aliphatic carboxylic acid ester of 17α-ethynyl-18-methyl-19-nortestosterone and a pharmaceutical carrier for said compound.
- -
-
-
- Synthesis of 13-alkyl-gon-4-ones
-
The preparation of 13-methylgon-4-enes and novel 13-polycarbonalkylgon-4-enes by a new total synthesis is described. 13-Alkylgon-4-enes having progestational, anabolic and androgenic activities are prepared by forming a tetracylic gonane structure unsaturated in the 1,3,5(10),9(11) and 14-positions, selectively reducing in the B- and C-rings, and converting the aromatic A-ring compounds so-produced to gon-4-enes by Birch reduction and hydrolysis.
- -
-
-