Stereoselective Synthesis of the C1-C16 Fragment of the Purported Structure of Formosalide B

Srinivas Gajula; Aedula Vishnu V Reddy; D Prabhakar Reddy; Jhillu S Yadav; Debendra K Mohapatra

doi:10.1021/acsomega.0c01474

Stereoselective Synthesis of the C1-C16 Fragment of the Purported Structure of Formosalide B

ACS Omega. 2020 Apr 23;5(17):10217-10224. doi: 10.1021/acsomega.0c01474. eCollection 2020 May 5.

Authors

Srinivas Gajula^{1

2}, Aedula Vishnu V Reddy¹, D Prabhakar Reddy^{1

2}, Jhillu S Yadav¹, Debendra K Mohapatra^{1

2}

Affiliations

¹ Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
² Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India.

Abstract

The first stereoselective synthesis of the C1-C16 fragment possessing stereo-enriched fully substituted tetrahydropyran (THP) along with tetrahydrofuran (THF) rings of the proposed structure of formosalide B is described in 12 longest linear steps with 22% overall yield, starting from two cheap and commercially available 1,5-pentanediol and l-glutamic acid, following a convergent approach. The key steps involve in this synthesis are Horner-Wadsworth-Emmons reaction, Sharpless asymmetric dihydroxylation, and acid-mediated ketalization to assemble the substituted THP ring, one-pot Sharpless dihydroxylation-S_N2-type cyclization, and Wittig homologation to construct the THF derivative.