The development of a complementary pathway for the synthesis of aliskiren

Org Biomol Chem. 2015 Jan 28;13(4):1133-40. doi: 10.1039/c4ob01963f. Epub 2014 Nov 25.

Abstract

The synthesis of aliskiren (1), a recently marketed drug for the treatment of hypertension, is presented. The focus of our synthetic effort is to develop an efficient pathway for the synthesis of (2S,7R,E)-2-isopropyl-7-(4-methoxy-3-(3-methoxypropoxy) benzyl)-N,N,8-trimethylnon-4-enamide (2a), which has been used as the advanced intermediate toward aliskiren. After an extensive investigation of three different strategies designed to construct the E-olefin functionality in 2a by employing the olefin cross-metathesis, Horner-Wadsworth-Emmons (HWE), and Julia-type olefinations, we have established a new protocol for the synthesis of 2a with a substantially improved overall efficiency in terms of the yield (ca. 33%), and diastereo- and E/Z-selectivity. The key transformations were the Evans chiral auxiliary-aided asymmetric allylation for the synthesis of the appropriate chiral intermediates in excellent enantiomeric purity of higher than 97% ee and a modified Julia-Kocienski olefination for the highly selective construction of E-2a with up to 13.6:1 E/Z ratio from the chiral intermediates. Consequently, the results provide an appealing option for the synthesis of aliskiren.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry
  • Amides / chemical synthesis*
  • Amides / chemistry
  • Chemistry Techniques, Synthetic
  • Fumarates / chemical synthesis*
  • Fumarates / chemistry
  • Stereoisomerism

Substances

  • Alkenes
  • Amides
  • Fumarates
  • aliskiren