Synthesis of 6β-aminoestradiol and its biotin, acridinium, and fluorescein conjugates

Amination of 3,17 beta-Bis[(2-trimethylsilylethoxy)methoxy]-1,3,5(10)-estratriene-6-one (2) using NaCNBH4 and NH(4)OA afforded 3,17-bis(SEM)-6-aminoestradiol (3) as a mixture of alpha and beta-isomers in 60:40 ratio, Hydrolysis of rite mixture of 3 using HF and separation by preparative high-performance liquid chromatography afforded pure 6 beta-aminoestradiol (4) in good yield. The relative stereochemistry of the amino group in 4 was established by NMR. The biotinylated estradiol probe (7), chemiluminescent probe (9), and fluorescent probe (11), were prepared from 6 beta-aminoestradiol (4) and the corresponding biotin, 10-(3-sulfopropyl)-N-tosyl-N-(3-carboxypropyl)acridinium-9-carboxamide and 5-carboxyfluorescein N-succinimidyl esters in 43-63% yields and >99% purity. (C) 1998 by Elsevier Science Inc.