... DIISOPROPOXY- AND DI-tert-BUTOXYETHYNE STABLE ACETYLENE DIETHERS ANNA Bou, MIQUEL A. PERICAS and FELIX SERRATOSA Departament de Qufmica Organica, Facultat de Qufmica, Univcrsitat de Barcelona ... a 2+2 cyctoaddition is observed, which will be reported in a separated paper (see footnote g). 1446 A. Bou al ... The reasons for this (instability have been studied theoretically by semicmpirical SCF MO methods: S. Olivella, MA Pericas and F ...