... References. 1; This procedure for preparation of 3 is superior to that reported in reference 2. It should be suitable for large-scale production of 3. 2.(a); .a AG Schultz, P. Sundararaman; Tetrahedron Lett., 25 (1984), p. 4591. ... Me); see Tetrahedron Lett., 21 (1980), p. 4233. b) PE Sonnett, RR Heath; J. Org. Chem., 45 (1980), p. 3139. 10; Schultz, AG;Lavieri, FP;Snead, TEJ Org. Chem., in press. ...