• For lithiation with LDA and addition to acetone in quantitative yield, see: J. Am. Chem. Soc., 95, 3050 (1973). Coupling of the lithio-derivative with esters gives high yields of t-butyl 3-oxoalkanoates: Synthesis, 45 (1985).
• Amino acids can be protected as their t-butyl esters, without prior N-protection, in the presence of perchloric acid in 1,4-dioxane: Liebigs Ann. Chem., 646, 134 (1961); or tosic acid and excess sulfuric acid: Org. Prep. Proced. Int., 18, 13 (1986). See Appendix 6. Mild transesterification of, e.g. methyl esters to the t-butyl analogues in the presence of catalytic KO-t-Bu has been reported: J. Org. Chem., 62, 8240 (1997).