C-2 dimethyl seco-mevinic acids. Synthesis of monocyclic HMG-CoA reductase inhibitors from (R)-(-)-carvone.
摘要:
An efficient preparation of novel monocyclic HMG-CoA reductase inhibitors from (R)-(-)-carvone is reported. Utilizing this chiral carbon pool, the C-2 dimethyl seco-mevinic acid 3a was prepared in 17 steps and 5.2 % overall yield. The key chiral intermediate aldehyde 10a was prepared via a short and efficient synthetic sequence (six steps, 27% yield) from (R)-(-)-carvone. The appropriate chirality of the diol acid side chain was secured by employing the chiral acetate synthon ''(S)-HYTRA'' and by performing a stereoselective 1,3-syn reduction on the beta-hydroxy ketone 19. Structural requirements at the C-2 position are rather stringent, and deletion of or addition of an extra methyl group are both unacceptable modifications for this novel class of monocyclic HMG-CoA reductase inhibitors.
Enantioselective Synthesis of Functionalised Decalones by Robinson Annulation of Substituted Cyclohexanones, Derived from R-(−)-Carvone
作者:Ben J.M Jansen、Cindy C.J Hendrikx、Nikolai Masalov、Gerrit A Stork、Tommi M Meulemans、Fliur Z Macaev、Aede de Groot
DOI:10.1016/s0040-4020(00)00110-1
日期:2000.3
catalysed conjugate addition of methyl magnesium iodide to cyclohexenones and trapping of the enolate as its trimethylsilyl enol ether, followed by a trityl hexachloroantimonate (TrSbCl6) catalysed Mukaiyama-reaction, was applied to R-(−)-carvone. This proved to be an efficient method for the preparation of C-2, C-3 functionalised chiral cyclohexanones. These compounds were converted into their α-cyano ketones
Scalable total syntheses of (−)-hapalindole U and (+)-ambiguine H
作者:Thomas J. Maimone、Yoshihiro Ishihara、Phil S. Baran
DOI:10.1016/j.tet.2014.11.010
日期:2015.6
produces a class of biogenetically related indole natural products that include hapalindoles and ambiguines. In this full account, a practical route to the tetracyclic hapalindole family is presented by way of an eight-step, enantiospecific, protecting-group-free totalsynthesis of (-)-hapalindole U that features an oxidative indole-enolate coupling. With gram-scale access to hapalindole U, the first total