The reaction of aldehydes 1 and 10 with Bu3SnH has been studied. In thermal conditions, after an initial chemoselective 6-exo-trig or 5-exo-trig cyclization to the aldehyde, a beta-scission reaction takes place, providing rearrangement products. At low temperature, using the Et3B/O-2 procedure, satisfactory yields of cyclohexanol 2 and cyclopentanol 11 are obtained. (C) 1998 Elsevier Science Ltd. All rights reserved.