Etienic etienate as synthon for the synthesis of steroid oligoester gelators

Linear oligoesters based on etienic acid (3β-hydroxyandrost-5-ene-17β-carboxylic acid) containing four steroid units were prepared using a 2 + 2 synthetic strategy in a successful synthesis of 3β-{[3β-({3β-[(3β-hydroxyandrost-5-ene-17β-carbonyl)oxy]androst-5-ene-17β-carbonyl}oxy)androst-5-ene-17β-carbonyl]oxy}androst-5-ene-17β-carboxylic acid. The main problems with deprotection were overcome by using orthogonal groups as O-nitrates and 2-(trimethylsilyl)ethyl ethers.