• For preparation of the Li salt and reaction with an acid chloride as an example of a method for esterification of hindered alcohols, see: Org. Synth. Coll., 6, 259 (1988). A general method for esterification of carboxylic acids using DCC and DMAP is illustrated for t-butyl ethyl fumarate: Org. Synth. Coll., 7, 93 (1990). For use of the same combination for the preparation of t-butyl esters of N-protected amino acids, see: Org. Prep. Proced. Int., 20, 180 (1988). See also Appendix 6.