... IR (Nujol) Y, 1620, 3340 cm-'; 'H NMR (CDCl,, internal Me4Si) 6 0.8 (d, CH3, J = 6 Hz ... The dry organic layer was evaporated and the residue recrystallized from hexane. ... de Chimie), Universitl de Clermont-Ferrand, 631 70 Aubiere, France, and Department of Chemistry, The Ohio ...