A compound of the formula:
1
wherein R
1
is H or a substituent; m is 1-3; Ar is an aromatic group which may be substituted; X is a bond or a divalent straight-chain group having 1-6 atoms which may be substituted; Y is —S—, —O—, or —N(R
2
)— (R
2
is H or a substituent group), Z is —N═ or —C(R
3
)═ (R
3
is H or a hydrocarbon group), ring A is a benzene ring; ring B is a 5- to 7-membered ring which may be substituted, or a salt thereof is useful for eliciting a prostaglandin I
2
receptor agonistic effect.
The first synthesis of coprinol has been achieved from 2-methoxy-3,5-dimethylbenzaldehyde via the intermediacy of an indanone derivative where dialkylation, Friedel–Craftsacylation, demethylation, and regioselective formation of a primary −OH group from a chloroacetyl group are the key steps.