Total synthesis and structural elucidation of spongosoritin A. Issue 8 (6th February 2018)

• Record Type: Journal Article
• Authors: Alcock, Lisa J.; Norris, Matthew D.; Perkins, Michael V.
• Is Part Of: Organic & biomolecular chemistry. Volume 16:Issue 8(2018)
• Page Start: 1351
• Page End: 1358
• Publication Date: 2018-02-06
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c7ob03150e
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : The total synthesis of two putative structures of spongosoritin A has established it's structure and absolute configuration as syn (6 R, 8 R ). Abstract : Two putative structures of spongosoritin A, with syn (6 R, 8 R ) and anti (6 S, 8 R ) configurations, were each synthesised in a total of 11 linear steps with only 8 purification procedures. The key steps in our strategy included Evans alkylation and olefin dihydroxylation to install the C8 and C6 stereocentres, a transacetalisation/dehydration cascade to construct the furanylidene core, and chromatographic separation of 9 E - and 9 Z -isomers of the final compounds with silver nitrate impregnated silica. Comparison of the 1 H and 13 C NMR data for the synthetic syn - and anti -isomers to that reported for the natural product revealed that the relative configuration of spongosoritin A is syn . The absolute stereochemistry was also confirmed as 6 R, 8 R based on optical rotation measurements where the synthetic syn (6 R, 8 R ) and natural product had the same sign of optical rotation (negative).