Abstract: Disclosed are retiferol derivatives of formula (I): wherein X is >C═CH2 or —CH2—; Y and Z are independently of each other hydrogen, fluorine or hydroxy; A is —O(CH2)3—, —(CH2)2-(1,2-C6H4)—, —CH═CH—(1,2-C6H4)—, —C═C—(1,2C6H4)—, —(CH2)2—CO—, —CH2—O—CO—, —CH2NHCO—, or —CH2NHCOCH2—; R1 is C1-C5-alkyl; R2 and R3 are independently of each other alkyl or perfluoroalkyl; and R4 is hydrogen, hydroxy, C1-C5-alkyl or C1-C5-alkyl or C1-C5-alkoxy; the use of such compounds to treat or present hyperproliferative skin diseases such as psoriasis, basal cell carcinomas, disorders of keratinization and keratosis; neoplastic diseases; disorders of the sebaceous glands such as acne and seborrhoic dermatitis; the use of these compounds in reversing the conditions associated with photodamage, particularly for the oral or topical treatment of the skin damaged through sun exposur