Preparation of nandrolone derivatives

7a-Ethylnandrolone (4c) and 7a-vinylnandrolone (4d) were prepared by 1,6-addition of Et2CuLi or vinylmagnesium chloride/copper(I), respectively, to A6-nandrolone derivatives 7a and 7b, followed by acidic hydrolysis and/or

Fig. 22.2 Preparation of testosterone and derivatives.
A6-Nandrolone acetate Fig. 22.3 Preparation of nandrolone derivatives 4a and 4b.

Experimental conditions:

A: 1) 7a, Et2CuLi, ether, THF, -30 oC; 2) TMSCl, -30 oC^ -10 oC; 3) NH Cl (aq). B: 1) 7b, CH2=CHMgCl, CuBr.Me2S (0.1 eq), LiSPh (0.1 eq), LiBr (0.1 eq), THF,

-15oC; 2) NH4Cl (aq). C: 1) HCl, acetone, RT; 2) KOH, MeOH, THF, H2O, RT (R' = Ac).

Fig. 22.4 Preparation of nandrolone derivatives 4c and 4d.

saponification (R = Ac) (Fig. 22.4) (van der Louw et al. 2003). Introduction of ethynyl by 1,6-addition is not possible. Instead, 7a-ethynylnandrolone (4e) was obtained from alcohol 9, which was produced from the A7-steroid derivative 8 by the method of KUnzer etal. (2003) (Fig. 22.5). Birch reduction of9 resulted in diene 10 which was converted by standard procedures to aldehyde 13. Wittig reaction with ClCH2PPh3Cl/t-BuONa and elimination of chlorovinyl compound 14 with n-BuLi produced ethynyl compound 15. Treatment of the latter with hydrochloric acid produced nandrolone derivative 4e. Detailed information on the synthesis of 7a-ethylnandrolone (4c), 7a-vinylnandrolone (4d) and 7a-ethynylnandrolone (4e) can be found elsewhere (van der Louw et al. 2003). Also included in this study is the new 7a-alkylated nandrolone derivative Org X, the structure of which will be reported later.

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