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Published on: February 7, 2019
Synthesis of the macrolactone core of (+)-neopeltolide by transannular cyclization
Gangavaram V M Sharma1, Sheri Venkat Reddy, Kallaganti V S Ramakrishna
1Organic and Biomolecular Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, India. esmvee@iict.res.in
Abstract:
The synthesis of the macrolactone core of (+)-neopeltolide has been achieved. The key synthetic strategy involves the highly diastereoselective synthesis of the 2,6-cis-disubstituted tetrahydropyran ring by a transannular cyclization of δ-hydroxy alkene using mercuric trifluoroacetate. Two of the six stereocenters C-5 and C-11 were realized from L-malic acid, while the remaining stereocenters C-3 (Sharpless asymmetric epoxidation), C-7 (transannular cyclization), C-9 (regioselective epoxide opening) and C-13 (chelation controlled reduction) were derived by asymmetric synthesis. The macrolactone ring was synthesized by macrocyclization using a RCM protocol.
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