It has now been discovered that, by forcing 3β,5α,6β trihydroxy 6α,17α dimethylpregnan 20 one from the reaction solution resulting from the methylation of 3β,5α dihydroxy 17α methyl 17β carbomethoxyandrostane 6 one under Grignard conditions and drying the crystalline product thus formed, {TAIL ~ a stable monomethanol solvate} is obtained free from {HEAD ~ methylated impurities} 
It has now been discovered that , by forcing 3β,5α,6β trihydroxy 6α,17α dimethylpregnan 20 one from the reaction solution resulting from the methylation of 3β,5α dihydroxy 17α methyl 17β carbomethoxyandrostane 6 one under Grignard conditions and drying the crystalline product thus formed , { TAIL ~ a stable monomethanol solvate } is obtained free from { HEAD ~ methylated impurities }
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