Synthesis 2009(14): 2293-2315  
DOI: 10.1055/s-0029-1216881
REVIEW
© Georg Thieme Verlag Stuttgart ˙ New York

Direct Methods for Stereoselective Polypropionate Synthesis: A Survey

Jun Lia, Dirk Menche*b
a Medizinische Chemie, Helmholtz-Zentrum für Infektionsforschung, Inhoffenstr. 7, 38124 Braunschweig, Germany
b Department of Organic Chemistry, University of Heidelberg, INF 270, 69120 Heidelberg, Germany
Fax: +49(6221)544205; e-Mail: dirk.menche@oci.uni-heidelberg.de;
Further Information

Publication History

Received 18 March 2009
Publication Date:
29 June 2009 (online)

Abstract

Polypropionates are key subunits in structurally diverse polyketide natural products and pharmaceuticals, rendering their synthesis an objective of high priority in synthetic organic and medicinal chemistry. A variety of methods have been devised for the direct and enantioselective assembly of the characteristic sequence of alternating methyl- and hydroxy-bearing stereogenic centers. This review presents a survey of well-established and more recently developed methods for the regio- and stereoselective assembly of polypropionates.

1 Introduction

2 Propionate Aldol Reaction

2.1 Auxiliary Control

2.2 Substrate Control

2.3 Organocatalytic Variants

2.4 Reductive Aldol Reactions

3 Crotylation

4 Allenylation

5 Epoxide Opening

6 [2,3]-Wittig Rearrangement

7 Sequential Substitution

8 Radical Processes

9 Intramolecularization

9.1 [2+2]-Cycloaddition

9.2 Silicon Tether

10 Conclusions

24

Li, J.; Li, P.; Menche, D. Synlett 2009, in press.

28

According to the (1,n)-nomenclature, 1 denotes the newly formed stereogenic center, while n stands for the pre-existing chiral center.