... Page 2. 1240 CH HEATHCOCK and D. GRAY 4 5 6 hinders approach of the C, carbon to Cs, so that intramolecular alkylation cannot occur. ... REFERENCES ' PC Mukharji and TK Das Gupta. Tetrahedron 8.5275 (1969) ' ' CH Heathcock, Terrahedron titers 2043 (1966); * C. H. Hcathcock, RA Badger and JW Patterson, J. Am. Chem. Sot. ... Vol. 2, Chapter 18. Holden-Day, San Francisco (1964) ' PC Mukharji. TK Des Gupta and DP Ghosh. ...