Tricyclo compounds, a process for their production and a pharmaceutical composition containing the same

A process for production of the compound of the formula:

• 18
• wherein
• R1 is hydroxy or protected hydroxy,
• R2 is hydrogen, hydroxy or protected hydroxy,
• R3 is methyl, ethyl, propyl or allyl,
• n is an integer of 1 or 2, and
• the symbol of a line and dotted line is a single bond or a double bond,
• and salt thereof, which comprises
• (a) culturing a FR-900506, FR-900520 and/or FR-900525 substance(s)-producing strain belonging to the genus Streptomyces in a nutrient medium and recovering the FR-900506, FR-900520 and/or FR-900525 substance(s) to give the FR-900506, FR-900520 and/or FR-900525 substance(s);
• (b) culturing a FR-900520 and/or FR-900523 substance(s)-producing strain belonging to the genus Streptomyces in a nutrient medium and recovering the FR-900520 and/or FR-900523 substance(s) to give the FR-900520 and/or FR-900523 substance(s);
• (c) introducing a hydroxy-protective group into a compound of the formula:
• 19
• wherein R2, R3, n and the symbol of a line and dotted line are each as defined above,
• to give a compound of the formula:
• 20
• wherein R2, R3, n and the symbol of a line and dotted line are each as defiend above, and Ra1 is protected hydroxy,
• or a salt thereof;
• (d) introducing a hydroxy-protective group into a compound of the formula:
• 21
• wherein R1, R3, n and the symbol of a line and the dotted line are each as defined above,
• or a salt thereof, to give a compound of the formula:
• 22
• wherein R1, R3, n and the symbol of a line and dotted line are each as defined above, and Ra2 is protected hydroxy,
• or a salt thereof;
• (e) reacting a compound of the formula:
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• wherein R1, R3 and n are each as defined above, and Rb2 is a leaving group,
• or a salt thereof, with a base, to give a compound of the formula:
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• wherein R1, R3 and n are each as defined above,
• or a salt thereof;
• (f) oxidizing a compound of the formula:
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• wherein R1, R3 and n are each as defined above,
• or a salt thereof, to give a compound of the formula:
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• wherein R1, R3 and n are each as defiend above,
• or a salt thereof;
• and
• (g) reducing a compound of the formula:
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• wherein R1, R2, n and the symbol of a line and dotted line are each as defined above,
• or a salt thereof, to give a compound of the formula:
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• wherein R1, R2, n and the symbol of a line and dotted line are each as defined above,
• or a salt thereof, and
• (h) removing a carboxy-protective group from a compound of the formula:
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• wherein R2, R3, n and the symbol of a line and dotted line are each as defined above, and Rb1 is protected carboxy(lower)alkylcarbamoyloxy,
• or a salt thereof to give a compound of the formula:
• 30
• wherein R2, R3, n and the symbol of a line and dotted line are each as defined above, and Rc1 is carboxy(lower)alkylcarbamoyloxy,
• or a salt thereof.