Westphalen-Lettre Rearrangement.
Th. Westphalen, Ber. 48, 1064 (1915)
H. Lettre and M. Muller, ibid. 70, 1947 (1937)
Petrow, J. Cheer. Soc. 1939, 998
Ellis, Petrow, ibid. 1952, 2246
Aebli et al., Helo. Chim. Acta 41, 774 (1958)
Rodig et al., J. Org. Chem. 26, 2431 (1961)
Rowland, ibid. 29, 222 (1964)
Blunt et al., Tetrahedron 21, 1567(1965)
Fieser, Fieser, Steroids (New York, 1959), p 325.