A novel synthesis of steroidal indoxyls and indoles

✍ Scribed by Alfred Hassner; Makhluf J. Haddadin

• Book ID: 104212272
• Publisher: Elsevier Science
• Year: 1962
• Tongue: French
• Weight: 123 KB
• Volume: 3
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70577-6

✦ Synopsis

IN attempts towards the synthesis of steroidal alkaloids1 we treated 5androstene-3B-ol-17-one with g-nitrobenzaldehyde in basic solution and obtained instead of the expected 16-(2-nitrobenzal) compound a yellow acidic product, m.p. 267-269' (dec.), in 75 per cent yield, to which structure Ia is attributed on the following grounds. 2 Ia gives a red-brown 2,f+-dinitrophenylhydrazone. It shows ultraviolet absorption (238, 262, 455 my; s 16,500, 25,000 and 5000 respectively) characteristic of indoxyls 3 but indicating further conjugation. Diazomethane or Fischer esterification converts acid Ia into a methyl ester IIa which is acetylated to IIIa or converted by Oppenauer oxidation into IV. Compounds I-IV clearly indicate the presence of N-H in the infrared and N.M.R. thus excluding a structure such as V. IIb obtained analogously from androstane-17-one via Ib had strong infrared bands at 3350 (N-H), 1725 (C02CH3), 1690 (conj. C=O), 1640