Dedicated to the memory of Professor Dr. Pierre CrahhP (24. XI. 88) Two gossypol analogues 2a and 2b were synthesized for biological evaluation as male contraceptive agents. The naphthol 8c was prepared by analogy with a known procedure starting from 3-isopropylcatechol (3). (t-Bu)?02-Mediated phenolic coupling of 8c furnished the binaphthol9c which, after pyrane ring closure, deprotection, and selective bisformylation with SnCI,/CI,CHOCH,, gave the target compound 2a. The corresponding tetrahydroxy analogue 2b was prepared in a similar way.

ChemInform Abstract The title compound (VII) as well as its tetrahydroxy derivative are prepared as analogues of the cotton-seed pigment gossypol (VIII) for biological evaluation as male contraceptive agents.