Diastereofacial Selectivity of Enolates

Article abstract of DOI:10.1021/jo00230a005

Results from our research in macrolide total synthesis prompted us to investigate ways of altering the diastereofacial selectivity of enolates without making major changes in the enolates' structure.The variation in the diastereofacial selectivity of enolates 7a-g derived from 3,4-syn-3-alkoxy-2,4-dimethylheptan-5-ones (5a-g) is presented.The parent enolate 7a was si-facial selective, while protecting the 3-hydroxyl group gave enolates that were re-facial selective (7b-g).Thus, without changing any chiral centers or backbone functionality, the diastereofacial selectivity of enolates can be varied or reversed.The implications of this finding to natural products synthesis are discussed.