Adducts of alkyl(phenylthio)ketenes to cyclopentadiene are cleaved with KOH-t-BuOK with retention of configuration at three centers. This observation broadens the synthetic potential of the method of vicinal alkylation of olefins. This method has been used for the vicinal addition of [Cm + Cn] units to cyclopentadiene.
Michel, P., Odonnell, M., Biname, R., Frisque-Hesbain, A.-M., Ghosez, L., Declercq, J.-P., Germain, G., Arte, E., & Vanmeerssche, M. (1980). Vicinal Alkylation of Olefins, Regioselective and Stereoselective Addition of [cm + Cn] Units To Cyclopentadiene. Tetrahedron Letters, 21(26), 2577-2580. https://doi.org/10.1016/0040-4039(80)80134-1 (Original work published 1980)