Syntheses in the series op lycopodiom alkaloids IV. A simple photochemical synthesis of an annotinine derivative

✍ Scribed by K. Wiesner; I. Jirkovský; M. Fishman; C.A.J. Williams

• Publisher: Elsevier Science
• Year: 1967
• Tongue: French
• Weight: 203 KB
• Volume: 8
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)90993-6

✦ Synopsis

At the outset of our studies directed towards the synthesis of various Iycopodium alkaloids, one of us (K.W.) proposed to approach the annotinine problem by a sequence which contained as a key step the novel photochemical Fredericton, N.B., Canada (Received 23 January 1967) addition I +II. It was not possible to utilize immediately this route because of difficulties which we experienced in the synthesis of the key compound I. Thus, the proposed photo addition was only studied or A7 cyclic model compound (1). The difficulties in the preparation of I have now been overcome and we wish to report a stereospecific synthesis of the annotinine degradatio product III by our photochemical method. The starting material for the preparation of I was the known and readily available vinylogous amide IV (?). Compound IV was heated for ninety minutes with a 156 excess of acrylic acid to 135'C. Under these conditions compound I was formed quantitatively and it was -purified by chromatograpw on silica gel. *(3) [ (CI,H,,NO,), m.p. 81-83'C.i m.v. (mass spec.) 205; I.R. (CHCl,) 1695, 1645, 1610 cm"; U.V. hmax 298 rnp (log t = . 4.1).]