New 3-substituted hydroxy-phenylboronic acid derivatives, useful in synthesis of non-steroidal Vitamin D3 analogs by Suzuki coupling to trifluoromethylsulfonyloxy-benzene derivative

摘要

Phenylboronic acid derivatives (I) are new. Phenylboronic acid derivatives of formula (I) are new. [Image] R : 2-4C alkyl; R1 : 1-4C alkyl, aralkyl, e.g. benzyl, tetrahydropyranyl or R3Si(R2)2; each R2 and R31-6C alkyl or aryl. Independent claims are also included for the following: (1) three methods for preparing (I); (2) method for preparing 3-bromo-4-(RCH2)-phenols (4); and (3) method for preparing non-steroidal analogs of Vitamin D3 that uses (I) in at least one stage.