Estradiol valerate - Synthetic Route 1
Estradiol valerate is a synthetic ester, specifically the 17-pentanoyl ester, of the natural estrogen, 17β-estradiol. It was introduced in the 1950s, and along with estradiol benzoate and estradiol cypionate, has since become one of the most widely used esters of estradiol. (Source: http://en.wikipedia.org/wiki/Estradiol_valerate).
Sasane, Sachin Arun; Ahire, Vijay Ashok; Vyas, Rajesh; Bhise, Nandu Baban; Singh, Girij Pal. Improved process for preparation of estradiol valerate and a novel crystalline form a of estradiol divalerate. Assignee Lupin Limited, India. WO 2012059803. (2012).