Vinyl Cyclobutanol Strategy for Halogenated Cyclopentanoids.

TLDR: The iodonium ion mediated ring expansion of the olefinic cyclobutanols 19, 20, and 22 gave the mixture of iodoalkylated cyclopentanones 27a-c and 28a−c, respectively as discussed by the authors.

Abstract: The iodonium ion mediated ring expansion of the olefinic cyclobutanols 19 , 20 , and 22 gave the mixture of iodoalkylated cyclopentanones 27a–c and 28a–c , respectively. On the other hand, the same reaction of 24 – 26 afforded stereoselectively the iodoalkylated cyclopentanones 27d and 27e .