Medium-Membered Ring Ketone Synsthesis. Synthesis of Oxa- and Aza-cyclooctanone Derivatives

抄録

As a model study on the synthesis of natural products possessing an eight-membered cyclic ether or amine framework such as laurencin (1) and FR900482 (6), two kinds of 2-benzyl oxacyclooctanones (7 and 8) and 2-methyl azacyclooctanones (9 and 10) were synthesized from the corresponding twelve-membered lactam sulfoxides (49-52) by applying our general method for medium-ring ketone synthesis. The corresponding lactam sulfides were readily prepared from the linear ω-tosyl carboxylic acids containing on oxygen atom (11 and 12) or methylcarbamate group (13 and 14) by condensation with 2-cyanoethyl 2-N-methylaminophenyl sulfide followed by alkylation.