Total synthesis of altohyrtin

Kary, P D, Roberts, S M, Watson, D J, Studies towards the total synthesis of altohyrtin A a convergent approach to the C38-C51 carbon framework. Tetrahedron Asymmetry, 10, 213-216, 1999. 

Total synthesis of altohyrtin A (spongistatin 1) Part 2. Angew. Chem. Int. Edit. Engl. 37, 192-196. 

The first total synthesis of altohyrtin C (spongistatin 2 4b) was accomplished via diastereoselective aldol coupling of the C1-C15 AB and C16-C28 CD segments, Wittig coupling of the ABCD and the C29-C43 EF segments, addition of the C44-C51 side chain to the fully elaborated ABCDEF system, and the regiose-lective macrolactonization (Fig. 8). 

The first total synthesis of (+)-altohyrtin A (spongistatin T, 4a) by Kishi et al. was accomplished via Wittig coupling of the C1-C28 ABCD and C29-C51 EF... 

The ABCD segment 538 was then constructed (Scheme 76). The Julia coupling of 528 and 535 followed by methylenation afforded adduct 536. The AB spiroketal system was constructed by functional group manipulation to give 537, which was converted into ketoaldehyde 538 via protective group manipulation and oxidation. The spiroketal 539, which is a key intermediate for Kishi s total synthesis of altohyrtin A (4a), was also synthesized from 537. 

Terauchi, T. Tanaka, T. Terauchi, T. Morita, M. Kimijima, K. Sato, I. Shoji, W. Nakamura, Y. Tsukada, T. Tsunoda, T. 2003. Formal total synthesis of altohyrtin C (spongistatin 2). Part 2 Construction of fuUy elaborated ABCD and EF fragments. Tetrahedron Lett. 44 7747-7751. 

Evans DA, Trotter BW, Coleman PJ, Cote B, Dias LC, Raja-pakse HA, Tyler AN. Enantioselective total synthesis of altohyrtin C (spongistatin 2). Tetrahedron 1999 55 8671-8726. 

Paterson I, Chen DYK, Coster MJ, Acena JL, Bach J, Gibson KR, Keown LE, ObaUa RM, Trieselmann T, Wallace DJ, Hodgson AP, Norcross RD. Stereocontrolled total synthesis of (+)-altohyrtin A/spongistatin 1. Angew. Chem. Int. Ed. 2001 40 4055 t060. 

Paterson, I., Chen, D.Y.-K., Coster, M.J., Acena, J.L., Bach, J., and Wallace, D.(. (2005) The stereocontrolled total synthesis of altohyrtin A/spongistatin 1 fragment couplings, completion of the synthesis, analogue generation and biological evaluation. Org. Biomol. Chem., 3, 2431-2440. 

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