Tetra-hydronaphthalenes

A process for preparing a compound of formula I:

• ##STR13## wherein R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl comprising:
• (a) reacting a compound of formula II:
• ##STR14## with a compound of formula III:
• ##STR15## wherein Hal is halogen;
• (b) acylating a tetrahydronaphthalene of formula IV:
• ##STR16## produced by the reaction in (a) to form a compound of formula V:
• ##STR17## (c) reacting the compound of formula V with an alcohol or a glycol to form a ketal of formula VI:
• ##STR18## wherein R' is an alkyl residue or R'--R' is a divalent alkyl residue that forms a dioxolane ring;
• and
• (d) reacting a compound of formula VI with magnesium and a formamide of formula VIII:
• ##STR19## to form a compound of formula I, wherein R.sup.3 and R.sup.4 are two organic residues or together form a ring.