Reaction of 3,4-estrone o-quinone (3,4-EQ) with several amino acid sid
e chain mimics, including 4-ethylphenol, 4-methylimidazole, acetic aci
d, and propanethiol, gave a mixture of several products including the
catechol, Michael addition products, and dimeric products of the catec
hol. On the other hand, several other amino acid side chain mimics, in
cluding ethanol, acetamide, 1-ethylguanidine, and 3-methylindole, did
not result in any addition products or catechol formation. Michael add
itions to 3,4-EQ with 4-methylimidazole, acetate, and 4-ethyl phenoxid
e resulted in 1,4-addition, leading to C-l adducts while reaction with
propanethiol gave the C-2 addition product.