摘要:
Reactions of stabilized sulfur ylides with chiral aldehydes provided epoxides with high stereoselectivity. The opening of the resulting epoxides with lithium dimethyl cuprate gave 2-methyl-3-hydroxy amides which represent potentially useful building blocks for the synthesis of macrolide natural products. These amides were transformed into chiral aldehydes, with a methyl group in the alpha-position, and were reacted, in a iterative process, with a sulfur ylide reagent to give, in high yield and stereoselectivity, the epoxides with the stereochemistry according to Felkin-Ahn control. Finally, opening of the epoxide with the Oilman reagent provided a compound with four stereocenters occurring in the macrolide-type of natural products. (C) 1999 Elsevier Science Ltd. All rights reserved.