Thiosteroids. XXIII. Diels Alder Reactions of 5'-Methylfuro-[4', 3', 2', -4, 5, 6] pregn-5-ene-3, 20-dione

抄録

5'-Methylfuro [4', 3', 2'-4, 5, 6] pregn-5-ene-3, 20-dione was treated with maleic anhydride, dimethyl acetylenedicarboxylate, dimethyl fumarate and benzyne, respectively, to yield the 1 : 1 adducts. The stereochemistry of these adducts was studied and the unexpected β-attack by the dienophiles was deduced from the NMR data.