The development of a 21-alkylation reaction which proceeds via the lithium 20(21)-enolate is described and its scope demonstrated by the preparation of a variety of 21-alkylpregnane derivatives. Application of this process to 11β-acetoxy-16α,17α-dimethyl-5α-pregnane-3,20-dione (28a) and its 5β-analogue (28b) led to the corresponding 16α,17α,21-trimethyl derivatives. Several routes from these saturated
描述了通过20(21)-烯酸
锂进行的21-烷基化反应的进展,并通过制备多种21-烷基孕烯衍
生物来证明其范围。将该方法应用于11β-乙酰氧基-16α,17α-二甲基-5α-孕烯-3,20-二酮(28a)及其5β-类似物(28b),得到相应的16α,17α,21-三甲基衍
生物。探索了从这些饱和的三甲基孕烷-3,20-二酮到11β-羟基-16α,17α,21-三甲基孕烷-1,4-二烯-3,20-二酮(Org 6216)的几种途径。最好的方法得到Org 6216,产率为75%。