OXAINDENE DERIVATIVES, PROCESS FOR PRODUCTION THEREOF (VARIANTS), PHARMACEUTICAL COMPOSITION ON THEIR BASE, ADMINISTERING AND MEDICAL TREATMENT

1. Oxaindene derivatives of general formula (I) wherein R1 represents lower C1-4 alkyl, lower C1-4 alkoxy or lower C3-6 cycloalkyl, R2 represents hydrogen, lower C1-4 alkyl or lower C3-6 cycloalkyl, R3 represents hydrogen, lower C1-4 alkyl, lower C1-4 alkoxy or benzyloxy, X represents hydrogen, an aliphatic C1-4-acyl or benzoyl or naphthoyl group, optionally substituted by one or more nitro or C1-4-alkoxy group(s) or a group of the formula R R =N-R wherein R , R and R each represent lower C1-4 alkylene, or R and R together with the nitrogen atom to which they are attached form a piperidyl or morpholinyl group, A and B together form an ethylene or a vinylene group, and n is 1, 2 or 3, stereoisomers and pharmaceutically acceptable acid addition salts thereof. 2. Compounds as claimed in Claim I, wherein R , R and R represent independently hydrogen, lower alkyl, X stands for hydrogen, A and B together represent vinylene and n is 1 or 2. 3. Compounds as claimed in Claim I, wherein R stands for lower alkyl, R and R represent independently hydrogen, lower alkyl, X stands for hydrogen, A and B together represent ethylene and n is 1 or 3. 4. Compounds of general formula (I): cis-4,6,7-trimethyl-2,3,3a,8a-tetrahydro-1H-8-oxa-cyclopenta[a]indene-5-ol, l,2,4-trimethyl-4b,6,7,8,9,9a-hexahydro-5H-10-oxabenzo[a]azulene-3-ol and cis-4,6,7-trimethyl-3a,8a-dihydro-3H-8-oxacyclopenta[a]indene-5-ol. 5. A process for the preparation of the compounds of general formula (I) wherein X represents hydrogen and A and B together form a vinylene group, reacting a hydroquinone derivative of general formula (II), wherein R , R and R are as stated in Claim 1 and R represents hydrogen or lower alkoxy, with a cycloalkene derivative of general formula (III), wherein n is as stated in Claim 1, in a solvent, in the presence of the catalytic amount of a strong acid. 6. A process according to Claim 5 characterized in, that catalytic hydrogenation of final products is additionally carried out for the preparation of compounds of general formula (1) wherein A and B together form an ethytelene group. 7. A process for preparation of compounds of general formula (I) (variant),wherein X stands for hydrogen, A and B form an ethylene group characterized in, that reacting a hydroquinone derivatives of general formula (II), wherein R , R and R as stated in Claim 1 and R represent hydrogen with cycloalkadiene derivatives of general formula (IV) in the presence of the catalytic amount of a strong acid. 8. A