in benzene byproducts: propane; to a refluxing suspn. of octahydroxycyclobutane in C6H6 during 20 min dropwise was added di-n-propyl(pivaloyloxy)borane; propane gas evolution for 1 h,; cooled, filtered, washed with pentane; further purifn. by high vac. sublimation at ca 130-150°C or by crystn. from a large vol. of toluene; elem. anal.;