519-11-9Relevant academic research and scientific papers
New routes to clavine-type ergot alkaloids. Part 1. First total synthesis of three natural products: (+)-setoclavine, (+)-isosetoclavine, (-)-9,10-dihydroisoseto-clavine, and structure correction of the latter
Moldvai, Istvan,Temesvari-Major, Eszter,Gacs-Baitz, Eszter,Incze, Maria,Doernyei, Gabor,Szantay, Csaba
, p. 291 - 298 (2006)
The double bond in ring D of (+)-9,10-didehydro-6-methylergolin-8-one (2) was reduced selectively by catalytic hydrogenation to yield (-)-6-methylergolin-8-one (6). Grignard reaction of 6 has been performed with methylmagnesium iodide to afford two isomers (5 and 7). The main isomer having an 8α-methyl group at C8 with a C/D-trans junction (5; (-)-dihydroisosetoclavine) proved to be identical with the natural product, hence its name and structure should be corrected. As a minor isomer (7) a C/D-cis clavine derivative was also isolated which can be regarded as unnatural (+)-8α-hydroxycostaclavine. (+)-Setoclavine (8) and (+)-isosetoclavine (9) have also been prepared from 2, thus achieving the first total synthesis of these natural products. Detailed structure elecidation of 5-9 has been carried out as well.
