1.
Org Lett
; 2(20): 3185-7, 2000 Oct 05.
Article
in English
| MEDLINE
| ID: mdl-11009377
ABSTRACT
A short synthesis of dragmacidin B (1), 2,5-bis(6'-bromo-3'-indolyl)piperazine (2), and corresponding didebromo analogues 8 and 9 is described. The key steps involve the dimerization of oxotryptamines 4 and 11 to give bis(indolyl)pyrazines 5 and 12, which upon selective reduction and reductive methylation with sodium cyanoborohydride afforded the requisite piperazine natural products.
Subject(s)
Indoles/chemical synthesis , Piperazines/chemical synthesis , Porifera/chemistry , Animals , Methylation , Oxidation-Reduction
2.
Org Lett
; 2(14): 2121-3, 2000 Jul 13.
Article
in English
| MEDLINE
| ID: mdl-10891245
ABSTRACT
[reaction: see text] A concise synthesis of topsentin A (R(1) = R(2) = H) and nortopsentins B (R(1) = Br, R(2) = H) and D (R(1) = R(2) = H) is described from oxotryptamine 5 via reduction of acyl cyanide 4. Regiospecific bromination of 3-cyanoindole afforded 6-bromo-3-cyanoindole (10) as the major product.