New synthesis of syn-stereodiad building block for polyketides. Formal synthesis of arenamides A and C

摘要

An efficient procedure has been developed for the transformation of (7S)-7-(3-bromoprop-1-en-2-yl)-5,5-dimethyl-4,6-dioxaspiro[2.5]octane [available from diethyl (S)-malate] into methyl 2-[(4S)-2,2-dimethyl-5-methylidene-1,3-dioxan-4-yl]acetate, and conditions for diastereoselective reduction of the double C=C bond in the latter have been optimized. The reduction product has been converted into (3S,4S)-3-[tert-butyl(dimethyl)siloxy]-4-methyldecanoic acid which is a building block for the synthesis of arenamides A and C, natural compounds possessing pronounced antitumor activity and efficiently inhibiting nitrogen(II) oxide and prostaglandin E-2 (PGE(2)).