Progesterone natural modification

Thus, through minor changes, beautiful in their simplicity yet dramatic in their effect, nature has excelled in molecular modification and man has learned from it. The living cell has transformed progesterone into a host of different modifications essential to its over-all economy, and through molecular modification, the chemist has done likewise. 

It, therefore, seems clear that the molecular modification of progesterone, altering its solubility, distribution ratio, polarity, protein- binding characteristics, steric requirements, crystalline structure, and rate of metabolism (as well as the nature of the metabolic products themselves), would alter some of the properties of progesterone, eliminate some, and introduce new and unexpected properties, many of which may not be evident even after extensive animal studies. 

Among the many naturally occurring processes leading to molecular modifications of progesterone and its precursor, pregnenolone, is the formation of the 17a-hydroxy derivative. Although 17a-hydroxyprogesterone... 

Due to the common occurrence of steroids in Nature, there is not much need to synthesize the steroid skeleton from simple substrates. Therefore, the use of phosphonates in syntheses involving this class of compounds, concerns mostly modifications of the steroid pool, like in the case of the conversion of 17-oxo-steroids to 20-ketosteroids and progesterone as well as construction of the South steroid subunit of cephalostatin 1 from hecogenin acetate. 

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