"Process for the preparation of a compound of formula (i) and process for the preparation of estetrol and estetrol" the present invention relates to a process for the preparation of a compound of formula (i) comprising the steps of a ) reacting a compound of formula (ii) with a silylating or acylating agent to produce the compound of formula (iii), wherein p1 is a protecting group selected from r2-si-r3r4 or r1co-, r1 is a group selected from alkyl C 1-6 or C 3-6 cycloalkyl, wherein each group is optionally substituted by one or more substituents independently selected from fluoro or C 1-4 alkyl； R 2, R 3 and R 4 are each independently a group selected from C 1-6 alkyl or phenyl, wherein each group is optionally substituted by one or more substituents independently selected from fluoro or C 1-4 alkyl； b) halogenating or sulfinylating the compound of formula (iii) to produce a compound of formula (iv)； wherein x is halo, or -o-so-r5 and r5 is a group selected from heteroaryl or C6-10 aryl, each group being optionally substituted by one or more substituents independently selected from chlorine or C1-4 alkyl； c) dehalogenating or desulfinylating the compound of formula (iv) to produce the compound of formula (v)； and d) reacting the compound of formula (v) with a reducing agent to produce the compound of formula (i).“processo para a preparação de um composto de fórmula (i) e, processo para a preparação de estetrol e estetrol” a presente invenção refere-se a um processo para a preparação de um composto de fórmula (i) que compreende as etapas de a) reagir um composto de fórmula (ii) com um agente sililante ou acilante para produzir o composto de fórmula (iii), em que p1 é um grupo protetor selecionado dentre r2-si-r3r4 ou r1co-, r1 é um grupo selecionado dentre alquila c1-6 ou cicloalquila c3-6, em que cada grupo é opcionalmente substituído por um ou mais substituintes independentemente selecionados dentre fluoro ou alquila c1- 4； r2, r3 e r4 são cada um independentement
