Heathcock synthesis

In contrast, the Mukaiyama aldol reaction used in the Heathcock synthesis of the C29-C44 fragment of spongistatin proceeded with comparatively reduced diastereoselectivity. The stereochemically complex enol silane 30 was eoupled to 29, a 2,3-57 -p-alkoxy aldehyde, resulting in... 

In the last fifteen years macrolides have been the major target molecules for complex stereoselective total syntheses. This choice has been made independently by R.B. Woodward and E.J. Corey in Harvard, and has been followed by many famous fellow Americans, e.g., G. Stork, K.C. Nicolaou, S. Masamune, C.H. Heathcock, and S.L. Schreiber, to name only a few. There is also no other class of compounds which is so suitable for retrosynthetic analysis and for the application of modem synthetic reactions, such as Sharpless epoxidation, Noyori hydrogenation, and stereoselective alkylation and aldol reactions. We have chosen a classical synthesis by E.J. Corey and two recent syntheses by A.R. Chamberlin and S.L. Schreiber as examples. 

HIYAMA - HEATHCOCK Stereoselectiveailylation Stereoselective synthesis o( anti homoaitylic alcohols by Cr promoted atlylation o( aldehydes. 

Guided by the desire to preserve the squalene chain for as long as possible, Heathcock s strategy for the synthesis of methyl homosecodaphniphyllate (1) defers the formation of a carbon-carbon bond between positions 2 and 3 to a late stage in the synthesis... 

W. R. Roush in Allylorganometallics The Uncatalyzed Reaction of Allylorganometallics with C = X Electrophiles in Comprehensive Organic Synthesis, C. H. Heathcock, Ed., Vol. 2, Perga-mon. Oxford 1991. 

B.B. Snyder in Comprehensive Org. Synthesis , Vol 2/Part 2, page 527 Editor C.C. Heathcock, Pergamon Press, Oxford... 

Heathcock CH (1991) In Heathcock CH (ed) Additions to C-X n-bonds, part 2. Comprehensive organic synthesis, vol 2. Pergamon, New York, p 181... 

An impressive example of a multi-step biomi-metic domino process is the synthesis of codaphni-phyllin by Heathcock et al. (see scheme 14). Another example is the highly efficient biomimetic synthesis of (+)-hirsutine by my group (see scheme 13). In addition several other total syntheses of natural products have been developed using domino processes these are described in the different sections of this chapter. 

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