Utilization of selenium-directed [2 + 2] cycloadditions: concise synthesis of (±)-fragranol

Abstract

The reaction of 2-(phenylseleno)prop-1ene 1 and methyl vinyl ketone 2 in the presence of EtAlCl₂ gave the [2 + 2] cycloadducts 3a and 3b. A radical substitution of the adducts 3a and 3b with allytributyltin gave the allylated cyclobutane product, which was transformed into the cyclobutane natural product, (±)-fragranol. Stereoselective radical substitution using the ethylene glycol ketals of compounds 3a and 3b was also achieved.