Tetrahydrofuran → 21-methylene-20(R)-methylpregn-4-en-3-one

반응식

[CH3:1][C@:2]12[CH2:19][CH2:18][C@H:17]3[C@@H:7]([CH2:8][CH2:9][C:10]4[C@:15]3([CH3:16])[CH2:14][CH2:13][C:12](=[O:20])[CH:11]=4)[C@@H:6]1[CH2:5][CH:4]=[CH:3]2.C(Cl)Cl.[C:24]([O:27]CC)(=[O:26])[CH3:25].[CH2:30]1[CH2:34]O[CH2:32][CH2:31]1>>[CH2:34]=[CH:30][C@@H:31]([CH3:32])[C@@H:3]1[C@:2]2([CH3:1])[C@H:6]([C@H:7]3[C@H:17]([CH2:18][CH2:19]2)[C@:15]2([CH3:16])[C:10](=[CH:11][C:12](=[O:20])[CH2:13][CH2:14]2)[CH2:9][CH2:8]3)[CH2:5][CH2:4]1.[CH3:1][C@:2]12[CH2:3][CH2:4][C@H:5]3[C@@H:14]([CH2:13][C:12](=[O:20])[C:11]4[CH:10]=[C:9]([CH2:25][C:24]([O-:27])=[O:26])[CH:8]=[CH:7][C:6]=43)[C@@H:15]1[CH2:17][CH:18]=[CH:19]2

참가 물질

반응물 3

HCID 8028Tetrahydrofuran

HCID 92979Androsta-4,16-dien-3-one

HCID 21226138Dichloromethane ethylacetate

생성물 2

HCID 1542966021-methylene-20(R)-methylpregn-4-en-3-one수율 48%

HCID 22873077Estra-1,3,5(10),16-tetraen-6-one-3-yl-acetate수율 48%

실험 절차

These syntheses are depicted in FIG. 178. Androsta-4,16-dien-3-one (4) was reduced at -55° with 5 lithium tris (1, 2-dimethylpropyl) hydridoborate in THF (c) as described for the preparation of 2 (FIG. 1). Chromatography on silica gel with CH2Cl2 /ethyl acetate 9:1 gave pure axial alcohol 5 (48% yield) and pure equatorial alcohol 6 (48% yield). Analytical samples were further purified by recrystallization (from PE at -30° for 5, from cyclohexane at RT. for 6).