Chromans and thiochromans with phenylethynyl substituents at the 7-position having retinold-like biological activity

A compound of the formula ##STR15## where R.sub.1, R.sub.2, R.sub.4 and R.sub.5 independently are hydrogen or lower alkyl of 1 to 3 carbons and R.sub.3 is hydrogen or lower alkyl;

• A is lower branched chain alkyl having 2 to 6 carbons, cycloalkyl having 3 to 6 carbons, alkenyl having 2 to 6 carbons and 1 or 2 double bonds, alkynyl having 2 to 6 carbons and 1 or 2 triple bonds, (CH.sub.2).sub.n where n is an integer between 0 to 5;
• and
• B is COOH or a pharmaceutically acceptable salt thereof, COOR.sub.8, COONR.sub.9 R.sub.10, where R.sub.8 is an alkyl group of 1 to 10 carbons, or a cycloalkyl group of 5 to 10 carbons, or R.sub.8 is phenyl or lower alkylphenyl, R.sub.9 and R.sub.10 independently are hydrogen, an alkyl group of 1 to 10 carbons, or a cycloalkyl group of 5 to 10 carbons, or phenyl or lower alkylphenyl.

A compound of the formula ##STR16## where R.sub.1, R.sub.2, R.sub.4 and R.sub.5 independently are hydrogen or lower alkyl of 1 to 3 carbons and R.sub.3 is hydrogen or lower alkyl;

• A is lower branched chain alkyl having 2 to 6 carbons, cycloalkyl having 3 to 6 carbons, alkenyl having 2 to 6 carbons and 1 or 2 double bonds, alkynyl having 2 to 6 carbons and 1 or 2 triple bonds, (CH.sub.2).sub.n where n is an integer between 0 to 5, and
• B is COOH or a pharmaceutically acceptable salt thereof, COOR.sub.8, COONR.sub.9 R.sub.10, where R.sub.8 is an alkyl group of 1 to 10 carbons, or a cycloalkyl group of 5 to 10 carbons, or R.sub.8 is phenyl or lower alkylphenyl, R.sub.9 and R.sub.10 independently are hydrogen, an alkyl group of 1 to 10 carbons, or a cycloalkyl group of 5 to 10 carbons, or phenyl or lower alkylphenyl.