1. Franck-Neumann, M.; Brion, F. Angew. Chem., 1979, 91, 736; Angew. Chem. Int. Ed. Engl., 1979, 18, 688. Exo and endo refer to the relative positions of the metal and the larger substituent of the uncoordinated double bond.
2. Rossi, R.; Diversi, P. Synthesis, 1973, 25. For the difficulty in generating the axial chirality of the allenic system in a well defined manner cf. Morrison, J. D.; Mosher, H. S. In Asymmetric Organic Reactions, Prentice-Hall, Englewood Cliffs, New Jersey, 1971, pp. 386–397. An important method for the asymmetric synthesis of optically active allenes is by conversion of centrodissymmetric compounds starting from previously resolved propargylic alcohols or derivatives:13–15 Colas, Y.; Cazes, B.; Gore, J. Tetrahedron Lett., 1984, 25, 845. Alexakis, A.; Marek, I.; Mangeney, P.; Normant, J. F. J. Am. Chem. Soc., 1990, 112, 8042 and references therein; Elsevier, C. J.; Vermeer, P. J. Org. Chem., 1989, 54, 3726 and references therein. The resolution of chiral allenes, mainly acids, by formation of separable diastereomers, is frequently only partial and critical in practice. See however the favorable case of pentadienedioic acid: Aso, M.; Ikeda, I.; Kawabe, T.; Shiro, M.; Kanematsu, K. Tetrahedron Lett., 1992, 33, 5787.
3. Leonard, N. J.; Boyer, J. H. J. Org. Chem., 1950, 15, 42.
4. Solladié-Cavallo, A.; Tsamo, E.; Solladié, G. J. Org. Chem., 1979, 44, 4189.
5. Franck-Neumann, M.; Martina, D.; Heitz, M. P. Tetrahedron Lett., 1982, 23, 3493. Franck-Neumann, M.; Martina, D.; Heitz, M. P. J. Organomet. Chem., 1986, 301, 61.