... Tetrahedron: Asymmetry. Volume 12, Issue 14, 14 August 2001, Pages 2059–2066. ... 1). 3. and 4. Another difference is that the ester hydrolysis of 6 and 7 proceeds with absolute enantioselectivity, whereas the ester butanolysis of 1, 2 and 7 (E=14, 50 and 12, respectively; ...