A new steroidal biradical

✍ Scribed by Kurt Metzner; Louis Libertini

• Book ID: 104213349
• Publisher: Elsevier Science
• Year: 1975
• Tongue: French
• Weight: 184 KB
• Volume: 16
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)71783-7

✦ Synopsis

We wish to report the synthesis of a steroidal nltroxyl biradical, IIIb, which in spite of its rather rigid structure was found to have an exchange energy (J) strongly dependent on solvent and temperature Ho&H-&" d b, R=O "I b, R=O III a, R = H b, R=O Ramasseul and Rassat have reported the synthesis and circular dichrolsm properties of the steroidal nltroxlde Ib.' Using a modified Sarrett procedure,* the amine precursor of this radical (compound Ia) was oxldlzed to the 3-keto denvative IIa (mp 107-108), ir(KBr)[3300 cm-l (NH), 3050 (CH olefin), 1710 (C=O), 1640 (C=C)l. 220 MHz nmr (CDC13) [6 1 0 S (19-Me), 1.14 S (18-Me), 4 8-5 1, 5.75-6.0 (6~ allylic)]. Compound IIa could be easily oxidized to the mononitroxyl radical IIb with m-chloroperoxybenzoic acid 3 esr (CHC13) [3 lines, a = 15.4 G]. Refluxing