Gulten, SirinSharpe, AndrewBaker, James R.Booker-Milburn, Kevin I.2025-01-272025-01-2720070040-4020https://doi.org/10.1016/j.tet.2007.02.064https://hdl.handle.net/20.500.12428/20684The intramolecular [2+2] photocycloaddition reactions of a series of alkenols tethered to ethanolamine, L-(+)-valinol and R-(-)-2-phenylglycinol derived 3,4,5,6-tetrahydrophthalimides via a carbonate or silicon linkage have been examined. These [2+2] photocycloadditions gave the corresponding cyclobutanes in high yield with complete endo control in all cases and with diastereoselectivities as high as 8:1 with the chiral tethers. The cleavage of the temporary tethers by either desilylation or hydrolysis provided the endo diols. Cleavage of the ethanolamine linkage by reduction/hydrolysis precipitated an acid-catalysed fragmentation/ring expansion sequence to generate complex tricyclic lactones. (C) 2007 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessphotochemistrycycloadditionstemporary tethersacidcatalysed rearrangementsArticle63183659367110.1016/j.tet.2007.02.064Q1WOS:0002482028000022-s2.0-33947656529Q3